The extra roster room gives teams -- particularly teams not in contention -- the opportunity to judge player development while giving them a taste of Major League competition. In this respect, the expanded roster is considered by some to be an early spring training. It has been criticized, however, for giving teams in contention too much roster flexibility during the pennant stretch. Nonetheless, September call-ups are not allowed to participate in the post-season as post-season rosters must draw from the pre-September 1st roster.