What is it? What is it that we're missing about Jeff Green? Because between what we've seen him not do, and years-long documentation of him not doing things, we just don't get it. Why was he selected fifth overall in the 2007 NBA draft? Why did he start for so long for the Oklahoma City Thunder? Why did the Boston Celtics trade a starting caliber NBA center for this guy? Why are they handing him a contract worth reportedly four years and $36 million? What aren't we seeing, here?

Green, for a start. Because of a frightening heart ailment that knocked out his entire 2011-12 campaign and somewhat due to the pell-mell nature of his minutes allotment during his short 2010-11 tenure with the C's, we haven't really seen Jeff Green play consistent minutes in 17 months or so. Of course, what we have seen in the seasons prior is no great guns — Green spent most of his time in OKC playing at power forward, but his rebounding percentages are lacking even for a small forward. And as a small forward, Green's ball handling and long-distance shooting leaves a lot to be desired.

So why would the Celtics follow through on the proposed one-year, $9 million deal that they offered Green before his heart condition was discovered? Why would they extend that offer? Why is he making the same money, just about, as 2012 Most Improved Player Ryan Anderson?

To be fair, the Celtics have done a terrific job this offseason at both developing depth, and staying under the luxury tax. Losing Ray Allen hurts, there's no way around that in spite of Jason Terry's eventual appearance in the green, but GM Danny Ainge has done well to re-hand Kevin Garnett a massive deal while working around the edges to try and develop a rotation. And Jeff Green, fully vetted as a wing apparently, will be relied upon due to the potential half-year absence of Avery Bradley, who will be out until midseason while he recovers from significant shoulder woes.

The payoff still doesn't seem right, though. Ainge appears to believe that Green can round himself into a Derrick McKey-type, which is admirable, but McKey's career 31 percent 3-point percentage would be out of place in today's spacing-intensive NBA despite his significant defensive gifts. Green shot 39 percent from behind the arc in his second season, but he's shot 31 percent in his three other seasons, so it's possible that his 2008-09 mark is a fluke at best. Sure, he could develop that stroke from the corner, but who pays a guy $9 million a year to develop?

Or to come off the bench? There's a chance the C's could go big-ish, and start Paul Pierce and Green as some cross-matched wing duo with Jason Terry coming off the pine; but until that lineup is developed, the C's are essentially paying starter money to Paul Pierce's backup.

Because the Celtics are so good — we mean it when we say they're a few good matchups and lucky strikes away from getting to the Finals again — Green's placement on the team doesn't hurt as much as it would a more middling outfit. This is a quibble for July, we're aware. But at $9 million? Even if you're doing his agent David Falk a solid?

The NBA — or, at the very least, two of its best GMs in Oklahoma City's Sam Presti and Ainge — has a soft spot for Green. There's something to his game that appeals that doesn't appear to be doing much either in the box score, the world of advanced metrics, the on/off the court numbers, or in straight up scouting. To us, he just looks like a guy that should be really, really good. Without actually getting there.

With, to Green's credit, a dogged intensity. The guy works hard, and we'd like him as a part of any roster.

We're just not sure of this price.