Colts safety Bob Sanders has reportedly had arthroscopic surgery on one of his knees while sitting out with an ankle sprain, according to ESPN.com. The procedure was performed so the recovery could coincide with that of Sanders' right ankle sprain, Colts owner Jim Irsay said Thursday. "The feeling was the high ankle sprain would take longer [to recover from] than the scope," Irsay said. "I think they just cleaned out a few things [in the knee]." Sanders is expected to be out for at least two more games.