Troy Murphy has chosen to complete his season with the Boston Celtics, according to Marc Stein. Murphy, a 6’10″ lefty who was once a double-double machine, picked Boston ahead of the Miami Heat. Apparently, Danny Ainge’s creative phone call worked.

Where does Murphy fit in with the Celtics? For now, he’ll probably play Chris Johnson’s minutes, which bodes poorly for the athletic stick figure who’s playing on a ten-day contract. Behind Nenad Krstic, Glen Davis, Kevin Garnett — and, whenever he returns to health, Shaq — Murphy figures to have a minor role (at best) in Boston’s playoff rotation. He adds depth, sure, but he likely will not be counted on if the Celtics remain healthy.

Theoretically, Murphy will provide a stretch-the-floor power forward who can rebound at an impressive rate. Of course, outside-shooting power forwards who don’t keep their bodies in good shape (I’m looking at you, Sheed) also don’t tend to maintain their jump shots very well. If the Celtics can get the 2009-2010 Murphy, who shot almost 40% from three-point range while also vacuuming rebounds, and use him as a fifth big — well, that’s depth, folks. But there’s some evidence to suggest the Celtics did not just sign double-double threat Troy Murphy, but a far lesser player.

All things considered, the Celtics just added a reasonably young (30 years old) power forward with size, rebounding acumen and shooting ability, for almost nothing. On the scale of risk-reward, the reward could be anywhere from almost nothing to pretty substantial. As for the risk? Maybe I’m wrong, but I don’t see any at all.