My gut reaction to hearing that Bruce Lee would be playable in EA Sports UFC was "Huh? That's a bit odd." In recent weeks, I've come around to find his inclusion to be in good fun.
If you remain unconvinced, here's a video in which various UFC figures do their best to justify his virtual debut in the Octagon. It's also a good look at him in the game, something we haven't seen a whole lot of up until now. Lee is unlockable by clearing the career mode or pre-ordering.