West chose to leave St. Joseph's after his junior campaign where he was selected by the Boston Celtics as the 24th pick in the 2004 NBA draft. In his first season, he struggled with injuries, playing a total of just 39 games, mostly coming off the bench. He averaged 4.5 points, 1.7 rebounds and 1.6 assists per game. After making the transition to point guard in his rookie season, West was named the starting point guard at the beginning of the 2005–06 season by head coach Doc Rivers.