The center was drafted in the first round with the 27th pick of the 2003 NBA draft by the Memphis Grizzlies, but was immediately traded along with Marcus Banks to the Boston Celtics in exchange for Troy Bell and Dahntay Jones, who had been selected by the Celtics in the same draft. During the 2004–05 season, Perkins received more playing time than he did his rookie season, and became known as one of the tougher players on the Celtics. He had a limited role during the regular season and playoffs as the team's "enforcer". Perkins was involved in an unusual scenario in the final seconds of regulation in Game 6 of the 2005 Eastern Conference first round against Indiana. Paul Pierce was ejected but Pierce was owed free throws because he had been fouled before the ejection. Under NBA rules, Indiana coach Rick Carlisle chose to select Perkins (who had not played in the game) off the bench to shoot the crucial free throws (the game was tied). Perkins missed both, indirectly leading the game going into overtime, in which the Celtics eventually won. After marked improvements during summer training and practice, Perkins earned more playing time from coach Doc Rivers during the 2005–06 season. He played some of the best games of his career in 2006, repeatedly reaching double figures in points and rebounds. After the trade of Mark Blount to the Minnesota Timberwolves, Perkins became the undisputed starting center for the Celtics, although he was already sharing starting time before Blount's departure. He started at center for the 2008 NBA champion Boston Celtics. In Game 6 of the 2010 NBA Finals, Perkins injured his knee and missed the rest of the game. He was inactive for Game 7, in which the Celtics fell to the Los Angeles Lakers. According to the Los Angeles Times, he suffered torn MCL and PCL ligaments in his right knee. Perkins did not return to the floor until January 25, 2011, when he logged 17 minutes off of the bench netting seven points, six rebounds and three assists in a win against the Cleveland Cavaliers. He received a standing ovation upon entering the game in the first quarter. After coming off the bench for his first 5 games back, Perkins returned to the starting line-up Friday, February 4 in a home loss to the Dallas Mavericks. He logged his first double-double of the