Still, the prospect of losing Beltran for even a game or two is troubling for St. Louis given his postseason pedigree. Beltran leads the Cardinals with a .400 postseason batting average. He has three home runs and six RBIs in the playoffs this year and leads all players with eight extra-base hits.
It's no fluke. Beltran is a career .375 hitter in the postseason, highest among players with a minimum of 100 at-bats. He has 14 homers and 25 RBIs in 137 postseason plate appearances.
Cardinals manager Mike Matheny wasn't sure what happened to Beltran.
"As he ran down his first at-bat, something caught him in his knee," Matheny said. "He came back down into the tunnel and checked him out and he was not doing well."
Beltran was not in the clubhouse after the game, but the St. Louis Post-Dispatch reported that he told the newspaper via text message late Wednesday: "I was running to first and when I passed the bag I felt a sharp pain ... close to the knee. I try to stay in the game but the pain was strong.
"I went to have an MRI and all the results came negative, everything was looking good.
"I am happy about that but I am also very sore."
Beltran appeared to move slowly down the line after grounding into a double play in the first inning. When the team took the field in the second, Carpenter was announced as Beltran's replacement.
Carpenter, in his first at-bat of the NLCS, followed Jon Jay's two-out single with a 421-foot home run against San Francisco ace Matt Cain in the third inning to put St. Louis ahead, 2-1. The Cardinals added another run in the seventh.
Carpenter is 2-for-6 this postseason and 5-for-5 in his career against Cain. The homer was his first extra-base hit off the right-hander.
The 35-year-old Beltran played in 151 games this season, sitting out occasionally with aches and pains -- sometimes with in his knee.
"He's had some issues on and off all season, on and off his whole career," Matheny said.