There are suddenly a lot of in-shape replacements available, but whether A). Strikeforce is capable of matching their salary requests, or B). the UFC will tie their contracts up in mediation if they have first crack at the Affliction rubble is up in the air. (Sobral had a pre-existing relationship with Strikeforce and remains their light heavyweight champion.)
Gilbert Yvel and some of the lighter-weight Affliction athletes might be within financial reach: Yvel, who is unlikely to be of interest to the UFC thanks to a spotty behavioral record and a lax ground game, made just $30,000 for a fight with Josh Barnett at Affliction II last January. He could probably be convinced to punch someone on short notice. He may be punching someone at this very moment, sans compensation.
Less likely: Vitor Belfort, who made $225,000 last January and would probably balk at taking a pay cut.