The New Jersey Nets selected JaJuan Johnson out of Purdue with the 27th overall pick, but immediately sent him to Boston for Marshon Brooks and a future second-round pick.

In Johnson the Celtics get a lanky, 6-10 forward with four years of college experience—and for the last three of those seasons he averaged over 2.0 blocks per game. Johnson also improved on the boards and at the line as a senior, finishing the year with 8.6 RPG and a 80.9% mark from the line.

Yes, there are a lot of issues with his skinny frame, but with a 7-2 wingspan he could develop into an elite defensive player, capable of guarding both forward positions.

Perhaps the person who should be most excited about Johnson is Celtics point guard Rajon Rondo, who will finally have a young, athletic player to toss alley-oop passes to. Of course, just how much time Johnson gets with Rondo is anyone’s guess.

If he’s lucky, Johnson will be relegated Boston’s bench, which finished the season ranking 26th among reserve units in scoring. However his presence, along with the continued development of Jeff Green and last year’s first-round pick Avery Bradley, could help establish an identity beyond Rondo and The Big Three. Right now Boston’s backups are defined by hefty Glen Davis, who hardly qualifies as a fast-break player. But with Bradley, Johnson and Green on board, the Celtics could have a significantly faster second unit than the one coach Doc Rivers used last season.

Besides his lean physique, there are some other concerns with Johnson. He has a decent mid-range jump shot, but he won’t be a 3-point threat at the NBA level—at least not for a few seasons. However Johnson’s positives simply outnumber his negatives. He can jump 38 inches, block shots, defend passing lanes and finish on the fast break, all of which should endear him to Celtics fans.