Boston, OKC pull last-minute trade stunner

The Celtics shipped big man Kendrick Perkins to Oklahoma City in a deal that included Jeff Green. (Elsa/Getty Images)

Celtics president Danny Ainge made a gutsy move just before the trade deadline passed Thursday afternoon when he dealt center Kendrick Perkins and guard Nate Robinson to the Thunder for forward Jeff Green and center Nenad Krstic.

Ainge knows that dealing Perkins will anger his fan base — and his veteran players, who were reportedly unhappy when they learned that the starter and soon-to-be free agent was gone. It does seem, at first, like a strange decision given Boston’s frontcourt issues. Shaquille O’Neal has been dealing with all sorts of leg injuries since his hot start; Jermaine O’Neal may not play again this season, depending on how he recovers from knee surgery; and Semih Erden, the Celtics’ Turkish rookie, is now a Cavalier after Boston sent him and Luke Harangody to Cleveland for a second-round pick Thursday — a move obviously designed to open up two roster spots for possible buyout guys.

And Krstic is Krstic — a nice player for 15 minutes a game, and a solid perimeter shooter and post defender, but not anywhere near Perkins’ level when it comes to defending the pick-and-roll and rebounding.

In short, the move appears to leave Boston’ front line very thin. And that’s an odd thing to do by a team that should be 100 percent concerned with winning the title this season.

But if you calm down and breathe, you can see Boston’s reasoning. (You don’t need to calm down and breathe to see Oklahoma City’s reasoning, by the way; the Thunder took a low-risk, high-reward gamble in trading Green, an overrated, impending free agent they didn’t want long term, for a legitimate defender at the center position – something general manager Sam Presti has coveted for years.)

Walk with me:

• According to The Boston Globe, the Celtics are receiving the Clippers’ 2012 first-round pick, which is only top-10 protected and came to the Thunder on a draft-day trade in 2010. For a team that has drafted near the end of the first round since 2007, that is not a small thing.

• The Cleveland trade freed up two roster spots that Boston will presumably try to fill with big guys. Maybe Troy Murphy. Maybe even Rasheed Wallace, as some are reporting, no matter how nauseating that seems. Ainge knows something we don’t; the Celtics will get the bodies they need to survive.

• Perkins is coming off massive reconstructive surgery on his right knee, and in Boston’s first game after the All-Star break, he strained a ligament in his left knee. It’s only logical to wonder if he’ll be healthy the rest of the season, after coming back and immediately playing nearly twice the number of minutes per game Boston had initially planned.

• Perkins recently rejected a contract extension that would have paid him about $22 million over four seasons, the most Boston could offer under current rules. That may have been the Celtics’ last and best offer, it turns out.

• Perkins will be a free agent. Glen Davis will be, too. In a league bereft of threatening centers outside that guy in Orlando and the pair of guys in Los Angeles, Ainge might rightly prioritize the better offensive player (Davis) in planning Boston’s future. As for the present, the Celtics are obviously comfortable giving 40 minutes per game in the playoffs to the Davis-Kevin Garnett combination at center and power forward. Big Baby/KG has been the crunch-time duo all season, and it may very well have been even in theoretical playoff matchups against Orlando and the Lakers.

• Boston badly needed a wing player to back up Paul Pierce after Marquis Daniels went down indefinitely with a bruised spinal cord. Green is now going to be that guy.

Let me be clear on this: Green is not as good as most folks believe he is. Being covered in the Thunder glow has lifted his reputation above where it should be. This is a 6-foot-9 power forward whose Player Efficiency Rating has never reached league average, who grabs a lower percentage of defensive rebounds than Pierce, and whose presence on the court has consistently turned the Thunder into a porous defensive team. When he’s on the bench, the Thunder are pretty stingy. When he’s on the floor, they’re the Raptors. Almost none of the Thunder’s best lineups feature Green. That trend has something to do with the other starters, but it has repeated itself in each of Green’s four seasons in the league.

He’s not quick enough to defend some small forwards or big enough to defend some power forwards. But as a backup? He can work, and Boston needs bodies. He’s capable of shooting a league-average percentage from three-point range, and Boston, averaging fewer three-point attempts than all but two teams, could use some floor-stretching. He can swing between both forward positions.

Green, like Perkins, is set to become a free agent, meaning Boston gets a free look at someone it drafted in 2007 (and subsequently traded for Ray Allen) to see if the 24-year-old Green might be a part of its future nucleus. If he’s not? Boston’s books suddenly look pretty clean in July 2012.

As for Robinson, he wasn’t going to be a factor in coach Doc Rivers’ playoff rotation — not a consistent factor, anyway. He might have provided one or two key scoring bursts, like he did last season, but he had floundered again as Rajon Rondo’s backup, and Boston has Delonte West to play that role as he gets healthy.

I’m not saying I love the trade for Boston, or even like it. But you can understand it. Ainge has done something risky here: He’s looking to the future while doing his best to maintain the present. He always said the Celtics of the late 1980s blew it by not addressing the future as aggressively as they should have when their key guys were in decline. He is doing his best to avoid that mistake while keeping the championship in play.

I imagine he’ll feel the same sort of pressure in the next two months that Magic GM Otis Smith feels today. There will be moments in the playoffs when Perkins’ absence will be tangible — if Dwight Howard scores easily on a back-down, or if Andrew Bynum and Pau Gasol grab a 1,000 offensive rebounds, as they did last season in Game 7 of the Finals when Perkins was in street clothes.

There is unease today in Boston. But don’t make declarations yet about this team torpedoing its title chances.

As for the Thunder, this is a brilliant move. They took two guys whom they clearly were not going to bring back next season (Kristic will also be a free agent) and flipped them for the tough-minded, defensive center they have longed for since their trade for Tyson Chandler fell through two years ago. This team has regressed badly on defense, and it was not going to be a serious contender in the playoffs unless it addressed that end of the floor. It has done so at the deadline, and without mucking up its salary-cap picture at all.

If Perkins doesn’t work out, Presti shrugs his shoulders and lets him walk, all with the knowledge that he didn’t give up much of value to take a chance on a center with a ring. Presti needs money to re-sign Russell Westbrook, Serge Ibaka and James Harden in the next few years, and that’s money he wasn’t going to spend on Green and won’t have to spend on Perkins if he doesn’t like what he sees.

But for now, if the Thunder put Perkins on the floor with Kevin Durant, Westbrook, Ibaka/Nick Collison and Thabo Sefolosha/Harden, they should be a top-10 defensive team.  I’m not buying them as a real championship threat, but they are closer now than they were a few hours ago. Like Atlanta’s acquisition of Kirk Hinrich on Wednesday, this move may be the kind of thing that has an impact bigger than we can predict now because of the team context.

We’ll see.