The left fielder was helped off the field in the seventh inning of the Pirates' 4-0 loss to the Mets after twisting his ankle in an at-bat against Johan Santana. Initial X-rays revealed no break in the ankle, but Moss will be reevaluated on Monday morning.
His status is unknown, but Moss said it is unlikely he'll be put on the disabled list. He said the pain is more toward the bottom of the ankle instead of a high-ankle sprain, which is a more serious injury.
"I swung and hit the ball, and when I went to plant on my back foot to get out of the box it just rolled over," Moss said. "It hurt pretty badly.
"It really did scare me because I haven't rolled my ankle since high school. It didn't feel like that. It was kind of a shock. Now, I'm pretty positive about it."
Steve Pearce replaced Moss in the Pirates' lineup. Moments after the game, Moss was found in the Pirates' clubhouse walking with crutches and with a black boot around his left foot.
"It calmed down a lot when he came into the training room," manager John Russell said. "[We'll see] how it reacts overnight and see what it does [Monday] to make a firm call."
"I kind of sat there for a minute and it kind of didn't go away for a second," Moss said. "We got up in the training room and it started feeling a good bit better. It's still sore, but it doesn't feel any like it did."
The injury comes at a bad time for the 24-year-old outfielder, who came from Boston in the Jason Bay trade. Moss was quickly benefiting from the move and was getting a chance to play every day.
He hit .193 with two home runs and five RBIs in his first 16 games with the Pirates.
"When it rains, it pours," Moss said. "First, I can't buy a hit right now no matter what I do. Then this comes. [The swing] started to feel a little bit better and this happens. But this is the way life is. You just got to deal with it."
Todd Krise is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.