Escobar was replaced in the top of the ninth inning after suffering a jammed right thumb diving for a ball, Angels manager Mike Scioscia said. Scioscia said Escobar is day to day and will be reevaluated on Friday.
Pennington left with no outs in the top of the fifth inning during Cardinals outfielder Stephen Piscotty's at-bat. The 31-year-old, who was 2-for-2 with an RBI at the time, said he felt cramping in his left hamstring, and was removed to avoid risk of further injury.
"It just cramped up," Pennington said of the injury. "It just didn't feel right and looked like it was going to cramp again. Instead of doing something to really actually hurt something, it was just airing it out."
Escobar, who was 2-for-4 on the game with a double and an RBI, was replaced by Geovany Soto. Soto, who was set to pinch-hit for Escobar when the final out was recorded in the eighth inning, came in as a defensive replacement and committed a throwing error that led to two unearned runs before leading off the bottom half of the inning with a double.
Pennington said he doesn't believe the hamstring will continue to be an issue.
"It definitely feels a lot better now than it did a couple hours ago," he said.
Scioscia added that while he doesn't expect either Escobar or Pennington to miss time by going on the disabled list, both will continue to be evaluated.
Injuries have continued to be an issue for the Angels, who just Sunday lost shortstop Andrelton Simmons for a minimum of six weeks after he injured his thumb against the Rays. Others who are currently on the shelf include right-hander Garrett Richards, left-hander Andrew Heaney, left-hander C.J. Wilson, left-hander Tyler Skaggs, right-hander Huston Street and left fielder Craig Gentry.
Fabian Ardaya is a reporter for MLB.com based in Anaheim.