Kansas City quarterback Joe Montana reportedly will retire because he doesn't expect to win a fifth Super Bowl, according to the San Jose Mercury News. Montana, who led the San Francisco 49ers to four Super Bowl victories, injured his left knee in December. He reportedly wants to have knee surgery that would end his career while letting him remain active without pain. Sources told the Mercury News that Chief's president Carl Peterson wants Montana, 38, to publicly pin his decision on the injury instead of the team's prospects. So far, both the Chiefs and Montana's agent deny that the three-time Super Bowl MVP, who was traded to Kansas City from San Francisco in 1993, is planning surgery or retirement.