Milwaukee Brewers first baseman Corey Hart was scheduled to undergo right knee surgery Tuesday, but he didn't go under the knife. Instead, Hart postponed the operation so he could seek a second opinion, MLB.com and the Milwaukee Journal Sentinel reported. The MRI of Hart's knee will be sent to Dr. Richard Steadman in Vail, Colo. "Until we get past this step, we don't know what the next step will be," Brewers assistant general manager Gord Ash said, according to the Journal Sentinel. "Time is of the essence, so we're hoping it won't be delayed that long. It's hard to say right now." If Hart isn't ready for the start of the season, his likely replacement at first base would be Mat Gamel. Hart had surgery on the same knee last spring to repair cartilage damage. According to the Journal Sentinel, Hart's knee swelled during offseason workouts and a recent MRI found a problem in the joint surface. In 149 games last season, Hart batted .270 with 30 home runs and 83 RBI.