If he makes the Hall of Fame (who would have guessed there would be an if to that question) he'd meet the Red Sox "10 Years and a Hall of Famer" rule.
Besides, nobody has worn his #21 since he left town for Toronto.
The Blue Jays could retire it.
The Yankees I'm sure thought they were when Clemens made his triumphant return in the sky box last spring.
Wouldn't it be odd if one of the great pitchers of all time retires and doesn't have his number retired anywhere?
Don't worry... the Astros will do it.
They retired Jose Cruz's number for God's sake.