Bears' running back Adrian Peterson underwent an emergency appendectomy on Monday night, according to a report on ESPN.com. Peterson, a six-year veteran, will miss the rest of Chicago's organized team activities this week. He will, hopefully, be able to work out again in two weeks. "I don't think it quite ruptured," running backs' Coach Tim Spencer told the Chicago Sun-Times. "They got it on time, so that will mean less time [out] for him."