MINNEAPOLIS -- Twins catcher Joe Mauer underwent a minor surgical procedure on his left knee recently, but he is expected to be ready to go by the start of Spring Training, Twins general manager Bill Smith said on Thursday.Mauer's procedure was performed by Dr. Joel Boyd, the same physician who performed surgery to repair a torn medial meniscus in Mauer's left knee back in 2004. This recent procedure, Smith said, was to help alleviate some irritation that was being caused by the plica band, which is a fold of tissue in the lining of the knee joint. Mauer had been bothered by inflammation in the knee toward the end of the 2010 season, causing him to miss nine games in late September. Smith stressed that this was a minor procedure and it should not cause any sort of setback for Mauer as he prepares for the 2011 season. "They believe that it will be no problem for him in Spring Training and that he'll be ready well in advance of Spring Training," Smith said.