The 2008–09 Boston Celtics season was the 63rd season for the franchise in the National Basketball Association (NBA). They started the season as the defending NBA champions, where they defeated the Los Angeles Lakers in six games, winning their seventeenth NBA championship, as well as marking their ninth series victory over the Lakers in the NBA Finals. The Celtics started the season 27–2, which surpassed a mark set by the 1966–67 Philadelphia 76ers for the best two-loss start in NBA history. This run also included a 19-game winning streak, which improved a Celtics franchise record set in 1981–82. However, the Celtics lost seven out of the following nine games, and eventually finished with a 62–20 record. The Celtics had the fifth best team offensive rating in the NBA. The team's star power forward Kevin Garnett suffered a season-ending injury in February. Despite not having Garnett, they defeated the Chicago Bulls in the first round in seven games, However, they lost to the Orlando Magic in the conference semifinals in seven games, eliminating them from the playoffs. The Magic would go on to the NBA Finals, their second NBA Finals appearance, only to lose to last year's Finals runner-up, the Los Angeles Lakers in five games. Until 2024, this was the last time that the Celtics won 60 or more games.

Key dates

Summary

NBA Draft 2008

On June 26, the Celtics selected shooting guard J. R. Giddens with the 30th and center Semih Erden with the 60th overall picks in the 2008 NBA draft, and traded cash considerations in exchange for small forward Bill Walker, who had been selected by the Washington Wizards with the 47th overall pick. Giddens had worked out with the Celtics before the draft for three days, and received praises from head coach Doc Rivers, who thought he could fight for minutes on the team right away. He was already familiar with future teammates Leon Powe and Kendrick Perkins, who were his teammates at the 2003 McDonald's High School All-American Game. Walker was considered a lottery pick, but suffered the third knee injury in his career during a workout at the Golden State Warriors facility on June 15. However, he remained in the draft despite the injury, and was expected to have minor surgery in July that would keep him out for three to four weeks. Erden was not expected to join the roster this season, and was seen by general manager Danny Ainge as their first-round pick in 2009.

Free agency

The Celtics headed into the off-season with several free agents and tried to gather a group to repeat as the NBA Champions, with a key decision on unrestricted free agent James Posey, who, in a widely anticipated move, opted out of the second and final year of his contract with the Celtics on June 30, but stated that he wanted to return to the Celtics on a new contract. P.J. Brown, who made key contributions during the 2008 NBA Playoffs, was leaning towards retirement, and the status of restricted free agent Tony Allen remained uncertain after the first-round selection of J. R. Giddens, who was seen as a possible replacement. Later it was revealed that the Celtics did not extend a qualifying offer to Allen, making him an unrestricted free agent. The Celtics also hoped to keep unrestricted free agent Eddie House, and decisions were to be made on unrestricted free agents Sam Cassell and Scot Pollard. The Celtics were interested in small forward Corey Maggette as a replacement for James Posey, but Maggette signed with the Golden State Warriors on a much higher contract than the Celtics were able to offer, which added to the urgency to re-sign Posey. On July 11, the Celtics addressed their need for a backup center by signing Patrick O'Bryant to a 2-year, $3 million contract, after he had an impressive workout with the team a week earlier, and consequently ruled out the return of Scot Pollard and P.J. Brown. Eventually, James Posey signed with the New Orleans Hornets on July 16, since the Celtics were reluctant to offer him more than a three-year deal at the mid-level exception. Compensating for the loss of Posey, the Celtics re-signed Tony Allen to a 2-year, $5 million contract, and were also able to re-sign Eddie House to a 2-year, $5.6 million contract, using the mid-level exception only on House. On August 22, the Celtics signed small forward Darius Miles, who was forced to sit out the previous two seasons due to microfracture surgery on his right knee and thought to have a career-ending injury, to a non-guaranteed contract, and expected him to fight for a roster spot at training camp. He worked out twice with the team and impressed with his health and attitude, but would sit out the first ten games of the regular season for violating the league's substance abuse policy if he made the roster. This signing ultimately put the roster up to the league maximum of 15 players, of which 14 players had fully guaranteed contracts. On September 29, the first day of training camp, Sam Cassell re-signed with the team, which put the roster one player over the maximum. On October 20, Miles was waived, a move which finalized the roster for the start of the season. On February 27, Stephon Marbury signed with the Celtics. In the following season he was offered a one-year contract for the veteran's minimum for $1.3 million but declined the contract.

Draft picks

Roster

Regular season

Standings

Record vs. opponents

Game log

18,624 18,624 18,165 18,291 19,136 18,624 22,076 18,624 18,624 18,624 17,952 18,624 18,624 19,107 19,800 18,624 18,624 19,177 18,624 18,624 18,624 16,102 20,173 18,624 18,624 18,729 18,624 18,624 18,624 18,997 19,596 16,029 20,651 18,624 19,763 17,112 18,624 20,562 19,800 18,624 18,624 17,578 18,624 19,600 17,461 18,624 18,624 22,076 18,624 16,831 18,624 19,763 18,624 18,080 20,285 19,911 18,422 19,784 18,609 18,624 18,624 15,791 18,624 18,624 19,600 18,624 18,134 22,107 18,624 18,797 18,119 18,624 17,461 20,054 18,624 18,624 18,624 18,624 18,624 20,562 17,752 18,624

Playoffs

Game log

18,624 18,624 23,072 23,067 18,624 23,430 18,624 18,624 18,624 17,461 17,461 18,624 17,461 18,624

Player statistics

Regular season

• Statistics with the Boston Celtics

Playoffs

Salaries

Awards, records and milestones

Awards

Week/Month

All-Star

Season

Records

Milestones

Injuries and surgeries

Transactions

Trades

Free agents

Additions

Departures