Moss twisted the ankle in the seventh inning of Sunday's game when he knocked a ground ball toward first and went to leave the batter's box. Moss didn't make it a step before falling to the ground. He had to be helped off the field and was not able to put any pressure on the ankle after Sunday's game.
One day later, Moss' ankle was sore -- as expected -- but had no bruising or swelling.
"There wasn't a whole lot of swelling, which was great," manager John Russell said. "He said it almost felt normal today. It's a good sign."
Moss also had the ankle reexamined by the Pirates medical staff on Monday, who, too, was encouraged by the lack of severity of the injury.
"I rolled it pretty good, but luckily nothing pretty serious happened," said Moss. "They said that everything is pretty positive on it because it didn't swell and it didn't bruise."
Moss will almost certainly be kept out of action for the team's upcoming two-game series in St. Louis, which begins on Tuesday. However, the Pirates are targeting their weekend series in Milwaukee as a realistic return date for Moss.
"If it makes as much improvement from today to tomorrow as it did from yesterday to today then hopefully it won't be long at all," Moss said.
In Moss' absence, Jason Michaels will assume the left field spot, while Steve Pearce will start in right field.
Jenifer Langosch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.