No official confirmation has been made yet, but it would not be a big surprise if he sat the game out. The 6'4, 320-pound nose tackle is in the running for the No. 1 pick in the NFL draft, and with lots of tape out on him already, it would not make much sense to risk injury in an exhibition game.
In his senior year, Lotulelei recorded 42 tackles (10 for a loss), five sacks and four passes defensed. He is arguably the most dominant defensive lineman in college since Ndamukong Suh. He's a natural fit for a 3-4 defense, but is talented enough to play in any defensive scheme.
I don't expect his draft stock to be hurt by skipping the Senior Bowl -- he doesn't have much left to prove until the Combine.