The New York Giants know it's time to make massive changes. The San Francisco 49ers know this is a lost season. A number of other teams realize they have to shore up holes and patch problems heading into the second half of the 2018 season, too.

How would NFL scouts and executives go about fixing the NFL's worst teams? We asked.

Each of the following teams sits in the bottom third of the NFL's standings as of Tuesday morning. For each, there are different philosophies on how to fix the roster.

Some include a complete teardown and rebuild. Others require teams to be patient and stay the course. In some cases, there are controversial ideas about what it would take to make the team competitive again.

So, how do you fix the worst teams in the NFL? Each starts with a quote from a league executive on what's required, followed by a plan to turn it around.

San Francisco 49ers

Scout's Take: "Can you heal an ACL? The biggest thing is drafting better. There are a lot of misses there from the last regime and this one."

The San Francisco 49ers went all-in this offseason, signing quarterback Jimmy Garoppolo to a massive five year, $137.5 million deal after he ended the 2017 season with a 5-0 record as a starter. They also signed top free-agent running back Jerick McKinnon to a four-year, $30 million deal.

Both are now done for the season with torn ACLs.

Perhaps it's just bad luck, and both will return in 2019 to help the 49ers make the playoff run that was expected this season. That's the hope from not only fans but also those in the front office.

In the meantime, San Francisco will focus on building a team around Garoppolo. 

How do you fix poor drafting? The team has to self-scout and learn from mistakes. Drafting Joe Williams or C.J. Beathard too early has robbed the depth chart of potential starters in value rounds. The same goes for the disappointing play of defensive end Solomon Thomas, the No. 3 overall pick in the 2017 draft.

It's easy to tell a team to draft better players, but the execution is far more difficult. General manager John Lynch came to the 49ers from a television booth and is still learning on the job, which is why Adam Peters has a high-ranking job scouting college players. 

With what is currently projected to be the No. 1 overall pick in the 2019 draft, the 49ers can select a difference-maker like Nick Bosa (EDGE, Ohio State) who will get onto the field immediately and give the defense a much-needed boost. 

Arizona Cardinals

Scout's Take: "They have time to blow it up and start over with a rookie quarterback and a few good pieces on defense. That's what I'd do."

The Arizona Cardinals selected quarterback Josh Rosen with the No. 10 overall pick in the 2018 draft after moving up in a trade with the Oakland Raiders. Rosen is the future of the team for at least three more seasons as the Cardinals try to determine whether he's the real deal and the franchise quarterback they need.

Outside of Rosen, the Cardinals do have a few other offensive building blocks. David Johnson is one of the NFL's best running backs. Larry Fitzgerald might be playing his final season, but rookie wide receiver Christian Kirk is talented. On the offensive line, left tackle D.J. Humphries has played well. Those pieces are enough to make the Cardinals more competitive than they have been.

On Monday, ESPN's Adam Schefter  reported that star cornerback Patrick Peterson has requested a trade. Earlier this month, Jason La Canfora of CBS Sports reported 2017 first-round pick Haason Reddick and 2014 first-round pick Deone Bucannon could be on the move ahead of the NFL's Oct. 30 trade deadline, too.

If Peterson and Reddick stay in Arizona, they should be considered top parts of the team's defensive foundation. The Cardinals also have Chandler Jones and Budda Baker as difference-makers on defense.

So, what's next?

Trust Rosen. Put him in position to succeed by hiring an offensive mind who will develop a scheme that gets the ball out fast and in space to limit the hits a lean, slower quarterback like Rosen will take. Perhaps interim offensive coordinator Byron Leftwich can be that person. The Cardinals have nine more games to figure it out.

Oakland Raiders

Scout's Take: "Blow. It. Up. They already traded their best player and got rid of another [Amari Cooper]. And [Derek] Carr should be next."

Head coach Jon Gruden is clearly unhappy with the Oakland Raiders' roster. Khalil Mack and Amari Cooper are gone. Safety Karl Joseph is on the trade block, according to Jay Glazer of Fox Sports. Quarterback Derek Carr will soon head into an offseason in which the Raiders could trade him, too.

The above executive thinks the Raiders should go all-in and tear down the roster.

Could this work? The Raiders do have three 2019 first-round picks and two 2020 first-rounders, as well as an extra 2020 third-rounder thanks to the Khalil Mack trade. Could Gruden add to that by moving Carr?

If so, the Raiders could potentially land a superstar prospect like Nick Bosa (Ohio State) and a wide receiver like N'Keal Harry (Arizona State) in the 2019 first round and then get a top-tier quarterback like Jake Fromm (Georgia) or Tua Tagovailoa (Alabama) in 2020 to pair with a safety or linebacker to shore up the middle of the defense. And that's without including any potential picks from a Carr trade.

The next 10 weeks will be pivotal for Gruden and Carr. The Raiders' decision-makers must learn if they trust Carr to be the leader they need to turn around a terrible season before making a move to Las Vegas.

New York Giants

Scout's Take: "Good luck."

Scout's Take II: "I would hate to be the Giants and need to draft a quarterback in this class, but they probably have to. I'd trade Eli [Manning] now and embrace being bad for a year."

NFL executives and decision-makers believe the New York Giants made a massive mistake by not selecting a quarterback of the future in either the 2017 or 2018 drafts. The team is now backed into a corner and could be forced to select a quarterback with a top-five pick in 2019, even if there isn't a can't-miss QB prospect in this year's draft class.

Scouts believe Oregon quarterback Justin Herbert could be worthy of a top-five selection, but rumors have persisted all season that he may return to school for his senior season and not enter the 2019 draft. If that happens, the Giants will be left with an empty cupboard at quarterback in the upcoming class.

With Odell Beckham Jr. and Saquon Barkley, the Giants do have the offensive firepower to quickly right the ship. Rookie guard Will Hernandez also looks like a star in the making. A good draft by the front office in 2019 could allow the Giants to get by for a year under 2018 fourth-rounder Kyle Lauletta and a veteran free agent with an eye toward the 2020 quarterback class.

One NFC executive threw out the following possibility, too: "Why not trade for Derek Carr? Send Manning to the Jaguars and go get Carr. It's a win for the Giants, a win for the Jaguars and lets the Raiders start over."

Indianapolis Colts

Scout's Take: "Luck is back. They have the front office to turn this around. Just keep rolling."

After a slow start to the season, Andrew Luck looks like his old self again. He's strung together four straight games with at least three touchdown passes and currently sits second in the NFL with 20 TDs.

Luck has done all of that with a rag-tag group at wide receiver and an offensive line that's improving but is still a work in progress. The Colts have a blue-chip quarterback again, which is where the fix starts.

General manager Chris Ballard and his scouts must now stock the roster with skill players and defensive stars like the gem they found in the 2018 draft, second-round linebacker Darius Leonard. With Leonard and 2017 first-rounder Malik Hooker, Ballard has two players around whom he can form his defense.

The Colts are unlikely to lose enough games to land Bosa from Ohio State, but players like Ed Oliver (Houston) and Devin White (LSU) are instant-impact defenders who are possibilities in the top five. 

Ballard, head coach Frank Reich and Luck form a trio that should give Colts fans hope for the future. The key is being patient enough to get through 2018 while watching young stars like Leonard, Hooker and Quenton Nelson develop into stars. 

Buffalo Bills

Scout's Take: "They're in trouble. The front office can't afford to miss. Who do you tap there as a building block?"

The Buffalo Bills traded up to select quarterback Josh Allen with the No. 7 overall pick in the 2018 first round, but we have yet to see if he can be their long-term answer. An elbow injury is currently sidelining him, and Buffalo's lack of reliable weapons at wide receiver have made it difficult to evaluate him thus far.

The Bills also moved up in the draft to select linebacker Tremaine Edmunds with the 16th overall pick. If they do currently have a building block, it's on defense, whether it's Edmunds and/or defensive backs Tre'Davious White and Micah Hyde. Those three could be a potential strength for Buffalo moving forward.

As the executive said, the Bills cannot afford to miss in the 2019 draft. The offensive line needs to be beefed up. They need more help at wide receiver, too. Buffalo eventually has to get younger at running back. And that's just on offense.

It's a tough task for general manager Brandon Beane, who will head into a pivotal offseason with a major rebuild in front of him.

Cleveland Browns

Scout's Take: "Trust what they're doing, but the most important decision is getting the right coach in place. This is a playoff team in the next three years if John Dorsey gets the right head coach."

NFL executives believe the Cleveland Browns are on the up-and-up.

Quarterback Baker Mayfield, tight end David Njoku, wide receiver Jarvis Landry and the running back duo of Nick Chubb and Duke Johnson make this an exciting offense to watch grow together. Defensively, the roster is loaded with Myles Garrett, Christian Kirksey, Joe Schobert, Denzel Ward and Damarious Randall.

That's encouraging, which is something no one would have said a year ago.

Dorsey now needs to find a coach who can help the talent assembled realize its potential. 

The Browns are likely to go after an offensive mind to pair with Mayfield and his weapons. NFL decision-makers believe Oklahoma head coach Lincoln Riley may be a target, as could Iowa State's Matt Campbell. 

The difference now is that the Browns have a roster and a general manager that coaches will consider. That's likewise something no one would have said a year ago. 

New York Jets

Scout's Take: "They have to stick by the young quarterback. And spend that money they have in free agency."

The New York Jets have a quarterback they believe in—Sam Darnold was the only 2018 rookie QB to start in Week 1—and a solid group on defense led by Leonard Williams and Jamal Adams. The front office now must spend wisely in free agency to fill in an offensive depth chart that looks average.

With needs at pass-rusher and wide receiver, the Jets can spend their salary-cap space on impact players. And as we've seen in the past—they tried to trade for Khalil Mack and were a finalist for Kirk Cousins—the Jets front office will be aggressive this offseason.

Who to spend money on isn't the only hard decision Mike Maccagnan and his deputies must make. Head coach Todd Bowles is on the hot seat, so the Jets may decide to go with an offensive-minded head coach to give Darnold the spark he needs to take a Jared Goff-esque leap in his second season. 

For the Jets to become a contender again in the Tom Brady era of the AFC East, they'll have to spend wisely in free agency and also nail the first round of the draft in 2019.