X-rays on Stewart's left wrist came back negative, Rob Biertempfel of the Pittsburgh Tribune reports. Stewart exited Sunday's game after his hand caught the backswing in one of pitcher Johnny Cueto's at-bats. No fractures were revealed, but he does have a serious bruise on his left hand, and should be considered day-to-day moving forward. Russell Martin (hamstring) will likely be ready for Wednesday's NL Wild Card matchup, but if not, Stewart would be the likely backup, provided the swelling goes down.