Cellular Field. Mauer underwent arthroscopic knee surgery after the 2010 season, and missed most of spring training due to a difficult recovery from the operation. After further difficulties during the first days of the season, he was placed on the disabled list immediately after the Twins' game on April 15. Team doctors believed his problem, termed a "bilateral leg weakness", was due to too light a workload during spring training. Mauer returned to game action as a designated hitter in extended spring training on May 25, and made his first post-DL appearance as a catcher in another extended spring training game on June 2. The following week, he went on a further rehabilitation assignment to the Twins' Class A affiliate, the Fort Myers Miracle, a team managed by his older brother Jake. After Mauer caught several games with the Miracle, it was speculated he could return to the Twins as early as June 16 or 17, but Twins manager Ron Gardenhire did not commit to a return date. Joe Mauer returned to play with the Minnesota Twins on June 17, 2011 and received a standing ovation from the fans. He made his first Major League start at first base on July 7, 2011, in Chicago, where he turned the first ball hit to him into an unassisted double play. In all he had 13 putouts and 2 assists and went 3-for-5 at the plate with 2 RBI in a 6–2 victory over the White Sox. On August 18, 2011, Mauer played his first game in right field. He had 3 putouts and went 1-for-3 with 1 RBI in an 8–4 Twins loss against the New York Yankees. Mauer struggled the entire summer with various ailments, from complications due to surgery at the beginning of the season to a bout of pneumonia at the end of the season, and had undoubtedly the worst season of his career. He played in only 82 games all year (career 126 average per season, not counting the 35 games he played in 2004), batted only .287 (career .323), and caught only 52 games. He hoped to return to form in 2012. At the start of spring training, Mauer expressed strong dissatisfaction with the previous season, saying "I've kind of been answering...questions [about last season] all winter, and it left a bad taste in a lot of people's mouths, and mine included, but it's a new