ST. LOUIS -- Cardinals third baseman Jhonny Peralta is still dealing with the issues in his left thumb that arose shortly before the All-Star break, manager Mike Matheny said on Monday.
Peralta left Sunday's game in the fifth inning in a double switch that put Matt Bowman on the mound and Greg Garcia at third base. On July 5, Peralta left a game against the Pirates after one at-bat after experiencing discomfort in the thumb on a swing.
The pain kept him out two games; he pinch-hit on July 8 before returning to the lineup on July 9. He hit a home run on Saturday and went 0-for-2 on Sunday before exiting.
"It seems like on some of the check swings, or swings and misses, something is just kind of grabbing there," Matheny said.
The inflammation and discomfort are not in the same area of the thumb that was surgically repaired after an injury in Spring Training, according to Matheny.
Peralta missed the first 57 games of the season as a result of that surgery and was hitting .221 with five home runs and 13 RBIs since his return. With Aledmys Diaz taking over at shortstop after winning the starting job early in the season, Peralta had to return at third base.
"He had it looked at today, and the doctors could see it was still flared up a little bit," Matheny said. "The way it was explained to me is there was a hot spot in there, something got re-aggravated, and it just kind of seems to keep showing up."
With Peralta ailing, Garcia was in the lineup and at third base on Monday. Matheny is unsure how long Peralta will be out, saying the injury will continue to be evaluated.
"It's a violent movement, especially when you start talking about your hands going through the swing mechanics," Matheny said. "It's just something we'll just have to keep working our way through."
• Brandon Moss (sprained left ankle) and Matt Carpenter (strained right oblique) played catch in right field prior to Monday's game. It was the first time Moss was on the field warming up without a walking boot. Neither has a timetable for returning from the disabled list.
• Padres center fielder Jon Jay is on the DL with a broken forearm but still made the trip to St. Louis for the three-game series with the Cardinals. Jay was drafted by the Cardinals in 2006 and called up in 2010. He won a World Series with the team in 2011 before being traded last offseason for Jedd Gyorko and cash considerations.
"Those are guys I still talk to on a daily basis, and those are guys that are friends for life," Jay said of his former teammates. "It's definitely different walking into the visitors' side today, but obviously, I have a lot of fun memories of my time here, and it's great to be back here."
Nick Krueger is a reporter for MLB.com based in St. Louis. This story was not subject to the approval of Major League Baseball or its clubs.