Although Toronto’s head coach, Sam Mitchell, is a key protagonist in the Nets’ first-round playoff series against the Raptors, he may play an even bigger role in the offseason.

The coaching carousel is turning once again, and Mitchell is going to be a major player as several teams look to fill job openings. This may come as a surprise to some, considering that Mitchell just won Coach of the Year honors, but he’s in an odd situation. His contract expires at the end of the season, and in coaching circles, the conventional thinking is that players won’t respect a lame-duck coach. Indeed, it was one of the reasons Mitchell won the award — onlookers were amazed at how he kept everyone together despite seeming to have one foot out the door.

To understand why he appears to be on his way out, a brief history lesson is in order. Mitchell was the incumbent coach when the Raptors hired Bryan Colangelo away from Phoenix to be the team’s new president. Typically in these matters, the new guy upstairs wants to bring in his own choice for head coach, so an incumbent rarely lasts long — just ask Don Chaney. Thus, Mitchell’s days appeared numbered from the get-go.

He’s managed to last this long largely because when Colangelo took the job in February 2006, he agreed not to hire away any Suns personnel — including assistant coach Marc Iavaroni, who was long rumored to be one of his favorite coaching candidates — until the end of the 2006–07 season. So Colangelo was content to let Mitchell run the show until his preferred option became available.

Needless to say, Mitchell’s 47-win season and Coach of the Year award complicates matters. He’s effectively a free-agent coach, a rare occurrence that last played out when Seattle’s head coach, Nate McMillan, jumped ship for the Portland Trailblazers in 2005.

As such, Mitchell is the leading man in this summer’s coaching hunt. Teams such as Charlotte and Indiana are already rumored to have great interest in him. The Bobcat rumor mill has been churning for months now, while the Pacers — who formerly employed him as a player — more recently got into the discussion when their late-season collapse resulted in coach Rick Carlisle’s dismissal.

But first the Raptors will have to make a decision. It’s been speculated that they’ll do the “old-collegetry” routine, making Mitchell a contract offer they know will be exceeded by the Bobcats or Pacers with the expectation that he’ll take the better money elsewhere. That way the team can sell to its fans that the Raptors tried to keep the guy, as they bring in Iavaroni, Colangelo’s top choice to run the team.

The wild card is whether other teams might be interested in Mitchell — or Iavaroni. Including Toronto, six NBA teams currently have coaching openings, and at least two other coaching jobs could become available between now and draft day.

As a result, we could see bidding wars for top-tier candidates such as Mitchell and, yes, Larry Brown. In fact, it may end up being a more interesting season on the coaching front than it is with free agency.

It all starts with the Raptors, but here’s a look at the league’s other coaching openings and how they may be filled this summer:

CHARLOTTE: Bernie Bickerstaff stepped down after guiding the expansion team for three seasons, moving into a front-office role to help the team’s president, Michael Jordan. The Bobcats will push hard for Mitchell, and I suspect they’ll succeed. Considering the Bobcats are in a condition similar to where the Raptors were two years ago, it seems to be a good fit. Brown could also be a factor here, given his North Carolina ties.

INDIANA: It’s hard to know what direction the Pacers will go given the likelihood that they’ll blow up their roster this summer. Carlisle rubbed players the wrong way with his controlling tendencies at the offensive end, even though he loosened the reins a bit this year. Thus, the Pacers are likely to pursue somebody perceived as more of an up-tempo players’ coach. If it’s a guy who can develop young talent such as Ike Diogu, Danny Granger, and Shawne Williams, so much the better.

SEATTLE: The Sonics fired both their coach (Bob Hill) and general manager (Rick Sund) after the season; former Knicks coach Lenny Wilkens will oversee both hires in his capacity as Seattle’s vice chairman. The GM vacancy comes first, but don’t be surprised if the Sonics take a long look at Rick Adelman – a longtime Pacific Northwest resident who does his best work with offensive-minded teams like this one.

Dwane Casey, a former Sonics assistant who did admirable work in Minnesota before his inexplicable firing at midseason, is another possibility. That is, if Wilkens himself isn’t interested in a return to the bench.

MEMPHIS: The Grizzlies are another team looking for a new general manager, after Jerry West stepped down at the end of the season, and they are perhaps the biggest wild card in this year’s coaching search. As currently constituted, the gig is undesirable and they’ll probably end up hiring a relative unknown. But if they win the lottery, expect big names to suddenly show interest.

SACRAMENTO: Anybody want to coach Ron Artest this year? No? Anyone? Hello?

MIAMI: Oops, did I say that out loud? Pat Riley continued his season-long “maybe I’m here, maybe I’m not” routine, by making an announcement just before the playoffs started that hinted he’d stay on the bench for three more years, only to hedge on that immediately after his Heat looked very old getting swept by Chicago.

If Riley does decide to leave the sidelines, it wouldn’t shock anyone if the Heat made a run at the Florida Gators coach, Billy Donovan, who has already accomplished everything he can at the college level. Former Grizzlies head coach Mike Fratello would also be in the picture here.

ATLANTA: Another situation that remains fluid, because the Hawks haven’t said definitively that head coach Mike Woodson’s job is safe. One wonders if they’re waiting to see how they do in the lottery, and whether a lucky bounce of the pingpong balls could help them hook a bigger-name coach. If so it’s a shame, because Woodson did pretty well considering what he had to work with.

jhollinger@nysun.com