The incident marked the fifth time that Byrd had been hit by a pitch in a ten-day period. Byrd was placed on the 15-day disabled list the following day. Justin Berg was called up to take his place. After coming off his stint on the disabled list, Byrd wore a protective mask customized to his helmet in order to shield his weakened facial bones. After the 2011 season Byrd began practicing Muay Thai and started a new diet and lost 40 lbs. On April 21, 2012 Byrd was traded to the Boston Red Sox for Michael Bowden and a player to be named later. Minor league pitcher Hunter Cervenka was the player sent to the Cubs May 15. On June 9, Byrd was designated for assignment by the Red Sox in order to make room for Daisuke Matsuzaka, who was returning from the disabled list. On June 12, 2012 Byrd was released. On June 25, Byrd was suspended 50 games for testing positive for a banned substance. Byrd was placed on the restricted list and remained there until August 20. On February 1, 2013, Byrd signed a minor-league deal with the Mets. Byrd hit a walk-off 2 RBI single on April 7 for the Mets on their way to a 4-3 victory over the Miami Marlins. Before a game on June 5, 2013, Byrd joked with Mets teammate Anthony Recker that he was going to hit two home runs in the game. Byrd did hit two home runs in the Mets 10-1 win over the Washington Nationals. Byrd hit .285 with 21 home runs and 71 RBI in 117 games for the Mets before being traded to the Pittsburgh Pirates. On August 27, Byrd and John Buck were traded to the Pittsburgh Pirates in exchange for infield prospect Dilson Herrera and a player to be named later, identified on August 29 as Vic Black. In his first game with the Pirates, Byrd hit a 3-run home run in Pittsburgh's 7-1 victory over Milwaukee. In the 2013 National League Wild Card Game, Byrd went 2-4 with a home run and 2 RBI, as the Pirates defeated the Cincinnati Reds 6-2. On November 12, 2013, Byrd agreed in principle to a two-year contract worth $16 million to return to the Phillies. The deal included an $8 million club option for 2016 that vested based on plate appearances. Unlike his previous years, Byrd began to strike out more often. In 154 games of 2014, Byrd struck out 185 times while batting .264 with 25 home runs and 85 RBI.