Boston Celtics jersey history No. 44 - Jiri Welsch (2003-05) During his time suiting up for the Celtics, Welsh wore only jersey No. 44 and put up 8.5 points, 3.2 rebounds, 2.0 assists, and 1.0 steals per game. Content Original Link: https://sports.yahoo.com/articles/boston-celtics-jersey-history-no-130103292.html