Allen agrees to two-year deal with C's
Boston's Big Three will remain intact.
Allen, Paul Pierce and Kevin Garnett have led Boston to one title and another Finals appearance in three years together. Allen and Pierce became free agents on July 1, weeks after the Celtics fell to the Los Angeles Lakers in Game 7 of the NBA Finals.
Pierce quickly reached a deal to re-sign with Boston for four years and $61 million.
After Boston lost to the Los Angeles Lakers in seven games, Allen said, "It's obvious I don't want to be anywhere else."
Now all three aging stars will return in an effort to keep open the Celtics' championship window.
Allen, who averaged 16.3 points last season, turns 35 later this month, while Garnett is 34 and Pierce 32.
The Associated Press contributed to this report.