He was one of the 2008 Boston Celtics 'Big Three' and today he made his retirement official. Now the question is - should his #20 hang in the rafters at Boston Garden?

The 41-year-old Allen hasn't played in the past two years but kept open the possibility of joining with a team to go for another title. It never happened.

So his NBA career was 18 years along. Five seasons with the Celtics.

His trade from Seattle to the C's paved the way for the Kevin Garnett agreeing to be traded to Boston to join Allen and Paul Pierce to form the 'big three' and the title run.

Some Celtics fans soured on Allen when he agreed to sign with the Miami Heat in 2012.

It is interesting to note than no Celtics player has worn #20 since Allen left town.

So perhaps his number could join the other C's greats in the Garden rafters.

Check out his NBA top 10 moments...