Last offseason, seven NFL clubs hired new head coaches—all of them first-timers except Jon Gruden.

At a time when points are piling up, general managers are seeking innovative minds to elevate their roster talent. Even in Gruden's heyday, many viewed him as an offensive guru, and the Oakland Raiders hope he can recapture that title. 

Currently, the Cleveland Browns have the only known head coaching vacancy after showing Hue Jackson the door in October. It's likely more coaches on the hot seat will be forced out following disappointing seasons.

Before the coaching carousel spins, let's take a look at some popular names that have come up in the rumor mill. We'll also go through potential candidates who could land an NFL job based on their merit as successful coordinators in the pros or lead skippers on the collegiate level.

Bruce Arians, Former Arizona Cardinals Head Coach

It's not often the Browns' head coaching position lands on the short list of ideal jobs on the market. Former NFL head coach and current CBS analyst Bruce Arians put his name into the mix among potential candidates to lead the team in 2019.

According to NFL Network's Ian Rapoport, Arians would only come out of coaching retirement for a spot in Cleveland. "I would listen to the Browns," he said. "And only them. ... I've always loved Cleveland. The fans, shoot, one of the best groups in the league and when I called their game this past year, I got that feeling about them." 

Arians mentioned keeping Freddie Kitchens as the offensive coordinator and considering Gregg Williams as the defensive play-caller within his staff. It certainly makes sense, as quarterback Baker Mayfield has improved since the team fired Jackson and ex-offensive coordinator Todd Haley, throwing for 771 yards, nine touchdowns and an interception in the last three games.

Despite an influx of new blood coming into the head coaching ranks, Arians' track record should make him a strong draw for the spot. In five years with the Arizona Cardinals, he was 49-30-1 as a lead skipper. He also managed a 9-3 record as the Indianapolis Colts interim head coach during the 2012 campaign. However, according to league rules, that goes on Chuck Pagano's ledger.

Josh McDaniels, New England Patriots Offensive Coordinator

New England Patriots offensive coordinator Josh McDaniels left a sour taste in Colts general manager Chris Ballard's mouth when he accepted the head coaching job in Indianapolis and then backed out days after his team's Super Bowl loss to the Philadelphia Eagles.

Despite the turn of events, the Patriots play-caller will continue to garner outside interest for a head coaching position, per CBS Sports' Jason La Canfora. "Conversations with decision-makers on several teams expecting to hire new coaches in 2019 revealed no shortage of potential interest in McDaniels despite what occurred last year in Indianapolis," he wrote. 

In all 10 seasons with McDaniels, the Patriots offense has ranked within the top eight in points scored. Of course, he's working with one of the greatest quarterbacks of all time in Tom Brady. 

Regardless, the 42-year-old will certainly have options in the offseason because of the sustained offensive success in New England. It says a lot that reneging on a verbal agreement and an unsuccessful two-year tenure with the Denver Broncos (11-17) between 2009-10 haven't cooled McDaniels' buzz.

John DeFilippo, Minnesota Vikings Offensive Coordinator

Last offseason, John DeFilippo interviewed for the Chicago Bears' and Arizona Cardinals' head coaching vacancies. He eventually landed the offensive coordinator position with the Minnesota Vikings, which may further boost his resume.

As a quarterbacks coach in Philadelphia, DeFilippo worked with Nick Foles and Carson Wentz; both were instrumental in the Eagles' Super Bowl run last year.

Wentz experienced a major bump in production between his rookie and sophomore years in the league, more than doubling his touchdown total and cutting his interceptions in half. As a backup, Foles guided the Eagles through the postseason and won Super Bowl MVP. 

Former Eagles offensive coordinator Frank Reich deserves some credit for the team's success, but DeFilippo continues to optimize quarterback talent in Minnesota. Kirk Cousins is on pace to top his career-best single-season touchdown total. He's also completing a career-high 71.1 percent of his throws. 

When considering the success of quarterbacks working alongside DeFilippo over the last few seasons, teams will likely inquire about his services in the offseason.

Kris Richard, Dallas Cowboys Defensive Backs Coach, Play-Caller

Despite the focus on developing a quarterback to lead an offense, don't count out defensive coordinators as potential head coaching candidates. This year, Matt Patricia (Detroit Lions), Steve Wilks (Cardinals) and Mike Vrabel (Tennessee Titans) accepted offers for the lead position.

None of those coaches have a winning record, but teams will listen to defensive-minded instructors who intend to bring in a solid staff.

Kris Richard isn't just a defensive backs coach with the Dallas Cowboys. He's also a play-caller. Defensive coordinator Rod Marinelli confirmed that early in the season, per Dallas Morning News reporter Brandon George.

"Cowboys DC Rod Marinelli said Kris Richard called the defensive plays in Sunday's win against the Giants and primarily in the opener at Carolina. With Marinelli's input both on game day and through week," George tweeted.

As a play-caller, Richard directed the Seattle Seahawks' top-three scoring defense between the 2015-16 campaigns before a slip to 13th last year. He's sculpted a stingier unit in Dallas.

In 2017, the Cowboys surrendered 28 passing touchdowns. Through 13 weeks this season, the unit has allowed just 16 scores through the air. Byron Jones has made a smooth transition back to cornerback after playing safety over the last two terms. In a wider scope, Dallas fields the No. 3 scoring defense.

Richard's success has followed him from Seattle to Dallas, which may catch the eye of front-office executives. If paired with an innovative offensive coordinator, the 39-year-old could become an ideal candidate over the winter. He interviewed with the Buffalo Bills after the 2016 campaign and Colts last offseason.

Lincoln Riley, Oklahoma Sooners Head Coach

In a short period, Oklahoma Sooners head coach Lincoln Riley has risen through the ranks as a hot college coach who could make a splash in the NFL. In October, he faced the media and answered questions about rumors connecting him to the Browns vacancy (h/t Dylan Buckingham of The Franchise 107.7).

"I knew that was coming," he said. "No, not right now. You sit here and answer these questions and...I always want to be truthful. The truth is for me is I love Oklahoma. I love coaching here, I love college football. I certainly don't have that itch right now." 

Riley seemingly chose his words carefully in saying he doesn't "have that itch right now." At that point, his focus was on finishing the season strong and pushing for a College Football Playoff spot. The 35-year-old didn't fully dismiss his interest in the pros, either.

In 2017, as a senior at Oklahoma under Riley, Baker Mayfield threw for 4,627 yards, 43 touchdowns, six interceptions and became a Heisman Trophy honoree. There's compatibility between the two, which makes for an intriguing match if the Browns inquire about an interview at the end of the year.

Furthermore, Riley has been successful on the collegiate level, leading the Sooners to a 23-3 record and a CFP appearance over the last two years. Front offices seeking new faces may take their shots at luring the young guru from Norman to the NFL.

Brian Kelly, Notre Dame Fighting Irish Head Coach

In 15 collegiate seasons, Brian Kelly has a 113-56 record as a head coach, factoring in the NCAA sanction to vacate victories between the 2012-13 seasons because of academic misconduct.

He also possesses a winning record with three different programs: Central Michigan, Cincinnati and Notre Dame. 

According to Colin Cowherd on FS1's The Herd, NFL teams like what they see at Notre Dame. "I am told there are a couple of NFL teams that have been really impressed with Brian Kelly this year, that he is getting the most in 2018 out of Notre Dame football." he said. 

The CFP selection committee currently slots Notre Dame at No. 3 in the playoff bracket. Leading his program to 12-0 with a .705 winning percentage as a head coach, Kelly could draw some interest at the next level. Depending on the school's finish, he may decide to close his collegiate chapter for a bigger challenge while there are eyes on him. 

Jim Harbaugh, Michigan Wolverines Head Coach

Following a crushing 62-39 loss to Ohio State, there's some unrest in Ann Arbor. Michigan head coach Jim Harbaugh has lost all four games against Urban Meyer and the rival Buckeyes.

ESPN's Paul Finebaum offered his opinion on what Harbaugh should do next and then assessed his career—both collegiate and pro (h/t Austin Nivison of 247Sports):

"I really think Jim Harbaugh should give it up," he said. "He is not going to get it done there. I stipulate as long as Urban [Meyer] is at Ohio State because Urban could leave, and it could be easier I believe. He has not proven to be an elite college coach. I think Jim Harbaugh, overall, is a good football coach. I'm not about to disparage him, but he was a better pro coach and that’s where he ought to go."

As a head coach, Harbaugh hasn't spent more than four years in one place. He took his first job as a lead skipper at San Diego (three years) before spending four years apiece at Stanford and with the San Francisco 49ers. The 54-year-old just completed a fourth term with the Wolverines. 

The pattern doesn't suggest Harbaugh will leave Michigan, but he's not afraid to move around every few years to take on a new opportunity. Because of his successful tenure with the 49ers, leading the team to two NFC Championship Games and a Super Bowl, front-office executives should at least call his agent about a head coaching vacancy.

Matt Campbell, Iowa State Head Coach

Here's an under-the-radar name to watch: Matt Campbell. He has a 53-33 overall record as a head coach over the last eight years with Toledo and now Iowa State.

Typically, when assessing collegiate coaches, there's a focus on win-loss records, draft talent coming out of the school and the ability to develop a program.

In Campbell's case, it's his intangibles, per Bleacher Report's Matt Miller. "Matty [Campbell] is the next one you hear about a lot," said one former NFL general manager who now consults with NFL teams on hires. "Everyone you talk to raves about his character, his energy and how his players respond to him." 

As teams look for younger coaches who can connect with players in the locker room, Campbell's name could emerge as one to monitor if clubs choose not to go with retreads. Miller's report also points out the Browns would have interest in the Ohio native.

There's a link between Campbell and Browns general manager John Dorsey. As a Kansas City Chiefs executive, Dorsey selected running back Kareem Hunt in the third round of the 2017 draft. The tailback spent three of his four years at Toledo with Campbell as his head coach.