It doesn't always take long for regret to kick in after the NBA draft.

A handful of teams could already feel it. These seven likely wish they went in different directions, based on their rookie's early results and the success of others they passed on. 

A few teams also made trades that could already be chalked up as mistakes.   

The following draft-night decisions will be questioned for years to come.

Philadelphia 76ers

Regret: Trading the No. 3 pick and a future first-rounder for the No. 1 pick (Markelle Fultz)

It's too early to assess Markelle Fultz, who tried to play hurt and now finds himself sidelined. But seeing how special Ben Simmons is and how impressive Jayson Tatum looks in Boston, trading the No. 3 pick and a future first-rounder doesn't look as savvy or assuring today.

Forget about evaluating Fultz in a vacuum. The Philadelphia 76ers now have to ask about his fit alongside Simmons—whether he can maximize his potential playing off the ball, a role that takes away scoring and playmaking opportunities and rhythm, and turns him into more of a spot-up and third option (behind Simmons and Joel Embiid). 

But the Sixers also have to worry about Fultz's shoulder and jumper, the weapon he's leaned on for volume scoring, which is ultimately what pushed him atop NBA draft boards. He's changed his shooting form multiple times since joining the Sixers, and he didn't attempt a three-pointer in four games played.

It's an issue nobody could have seen coming and now has many wondering what's going on both physically and mentally with the No. 1 overall pick. Instead of dealing with the uncertainty around Fultz, the Sixers could have kept a future first-rounder and taken Tatum, who's emerged as an immediate contributor, ironically for his ability to adapt and score off the ball. 

Denver Nuggets

Regret: Trading down for the No. 24 pick (Tyler Lydon) and Trey Lyles 

Just 20 games in, it's safe to proclaim the Utah Jazz winners of their draft-night trade with the Denver Nuggets. 

Denver let the Jazz take their No. 13 pick and select Donovan Mitchell, who's arguably No. 2 in the Rookie of the Year race. In return, the Nuggets acquired Trey Lyles and the No. 24 pick, which they used on Tyler Lydon. 

Now in his third NBA season, Lyles is playing 11.2 minutes per game. And Lydon hasn't scored an NBA point.

The Nuggets apparently didn't have any problems stockpiling power forwards, so the excuse that they passed on Mitchell to avoid creating a backcourt logjam doesn't fly. The fact he's having a better season than Jamal Murray and Emmanuel Mudiay should only make Denver's regret hurt worse.

Chicago Bulls

Regret: Trading cash considerations for the No. 38 pick

After trading Jimmy Butler earlier in the night, the Chicago Bulls entered rebuilding mode midway through the draft. That's why it seemed odd they'd deal the eighth pick of the second round for cash considerations.

Jordan Bell would have given the Bulls' frontcourt extra pop Robin Lopez and Bobby Portis don't offer.

Instead, Bell is now in Golden State, providing his signature energy, athleticism and defense, which the Bulls rank No. 28 in.

Even if Chicago didn't love Bell, there were other potential role players available, including Dillon Brooks, Dwayne Bacon, Damyean Dotson, Jawun Evans and Sindarius Thornwell, second-rounders picked between Nos. 39 and 48 who've flashed glimpses early on.

Portland Trail Blazers

Regret: Trading the No. 20 and No. 15 picks for the No. 10 pick (Zach Collins)

Giving up two picks for one means a team feels extra confident in a specific prospect. The Portland Trail Blazers had their eyes on Zach Collins and gave up the 15th and 20th picks to secure their target.

But since he only played 17.3 minutes per game as a freshman at Gonzaga, mostly against mid-major competition, the Blazers didn't have much to go on. They also already had a center in Jusuf Nurkic, who the team presumably would want to build with long term.

Unless the Blazers don't plan on signing or matching offers for Nurkic in restricted free agency, they'll have traded two top-20 picks for a backup center. It's worth noting that John Collins, Justin Jackson, OG Anunoby and Kyle Kuzma all went No. 15 and later. And if they wanted another center, Jarrett Allen would have been available at No. 20.

So far, the only thing we've learned about Collins is that he's far away from contributing, having totaled three points, six rebounds and 10 fouls in seven appearances. 

New York Knicks

Regret: Drafting Frank Ntilikina over Dennis Smith Jr., Donovan Mitchell 

Still 19 years old, Frank Ntilikina appears on his way toward becoming a valuable defender and smart passer. But his scoring and playmaking skills are significantly behind the other guards the New York Knicks looked at before the draft. 

And there's only so much upside tied to a guard who struggles to create and finish.

Ntilikina isn't nearly as athletic or threatening with the ball as Dennis Smith Jr. and Donovan Mitchell, who would have both given New York needed firepower alongside Tim Hardaway Jr. 

Mitchell just set a Utah Jazz rookie record with 41 points against the New Orleans Pelicans. Ntilikina scored 41 points over an eight-game stretch from November 13 to November 27.

He still has the chance to be a fine, three-and-D role player for the Knicks, but when they look back in a few years, there is bound to be at least one player from their list of predraft targets they'll regret passing on at No. 8.

Detroit Pistons

Regret: Drafting Luke Kennard over Donovan Mitchell 

At No. 12, there were two available guards staring at the Detroit Pistons. They took the wrong one. 

The Pistons weren't the only ones to miss on Donovan Mitchell, but it should sting a little extra in Detroit, since it took Luke Kennard, who plays the same position, one pick before the Utah Jazz traded into the lottery for Mitchell. 

Kennard has looked fine early with his signature shooting (41.5 percent 3PT). But Mitchell is on a whole other level in terms of per-game production (16.4 points, 3.3 assists), and between his athleticism, scoring potential and defensive versatility, there is no debating who offers more upside.

With Ish Smith leading the Pistons' reserves in scoring average (9.2 points), Mitchell would have given Detroit's bench needed offense.

Milwaukee Bucks

Regret: Drafting D.J. Wilson over John Collins 

The Milwaukee Bucks own the league's second-worst rebounding percentage. And they passed on John Collins for D.J. Wilson in June. 

Averaging 11.1 boards per 40 minutes, Collins leads all rookies with a 20.5 player efficiency rating (minimum 18 minutes per game). NBA-ready to clean the glass and score in the paint, Collins could have helped the Bucks right away.

He's also roughly five months younger than Wilson, who wasn't nearly as productive in college and has played just 35 minutes all season. 

Stats courtesy of ESPN.com, RealGM.com