It wasn't so much a change to the roster size, as roster limits were still fixed at 25, but teams had long had the option of carrying 24 players, but only ever did for brief periods of transition, between transactions. During a period of labor hardball (1985-ish-through-1987-ish), the teams agreed with each other to carry 24 players only. Newspapers mocked them, saying that a team would cave and add a player as soon as one was needed, especially in the post-season. But the Mets marched in lockstep, carrying only 24 through the 1986 post season. This widely understood unofficial agreement was cited in the collusion lawsuits that followed. Peter Ueberroth was looking to be the commissioner that rode in on a white horse and saved baseball from itself, but his short tenure led to the owners ultimately losing three straight collusion suits. Now, as a rule, 25 guys get paid for the day, even if only 22 are in the dugout.