In 2004, during the Kansas City Royals disastrous 58–104 season he was released on June 18. On June 22, he was picked up by the Boston Red Sox and then made three appearances during the 2004 ALCS against the New York Yankees and was credited with the Game 4 win. His innings of shutout baseball during Game 4 were the last he would ever throw; he retired following the 2004 season. He did make a return to Fenway Park for Opening Day 2005; there he received his World Series ring, as well as a large ovation. For Opening Day 2008, he got to carry out the World Series trophy.