Pitching isn’t exactly like riding a bike, but as long as Peavy’s mechanics are fine, his command should come back to him. It’ll take repetition before his command is back to where it was from May-July of 2010, but it should come back quicker than his velocity and stamina. That being said, whatever results Peavy sees in spring should be taken with a grain of salt given his command will take some time to return. But, if by some miracle, his command returns after a handful of spring outings and he’s able to locate within the strike zone well, his return schedule could be sped up.
I’d argue Randy Williams went through stretches like that because he wasn’t very good, but Jim is certainly right that Ohman is actually the fourth-most effective reliever against lefties in the team’s bullpen. His lone job likely will be solely to retire left-handers, and those situations likely will be earlier in games (like, the sixth inning).