The St. Louis Cardinals are in position to finish with the NL's best record for the second time in three years, but they may have trouble on their hands - or more specifically, on Yadier Molina's thumb.

St. Louis hopes to learn good news regarding Molina's latest injury ahead of Monday night's series opener against the visiting Cincinnati Reds.

The Cardinals (93-56) are the only team to have already clinched a playoff spot and own a four-game lead in the NL Central over Pittsburgh, which has baseball's second-best record. St. Louis avoided a sweep by the Chicago Cubs on Sunday with a 4-3 victory, but the mood surrounding the club isn't exactly cheerful as it returns home from a 5-5 trip.

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Molina sprained his left thumb tagging out Anthony Rizzo on a sac fly attempt in the eighth and is scheduled to undergo an MRI on Monday. The 12th-year catcher is batting .270 with 61 RBIs - ranked third on the team - and the Cardinals are 5-8 when he doesn't play.

"I'm concerned," manager Mike Matheny said. "We're anxious to hear what the doctor is going to report."

St. Louis has dropped six of nine in this season series after winning six of the first seven meetings, and is hoping to flip the results of a pitching rematch from Sept. 10.

Six runs allowed over 4 1-3 innings in that 11-0 Cincinnati victory were both season worsts for Jaime Garcia (9-5, 2.52 ERA).

He looked better his last time out Wednesday at Milwaukee, though his numbers didn't necessarily reflect that due to a big inning. He allowed four runs - all in the fourth, including a three-run homer - over 6 1-3 innings in the 5-4 victory.

"I was able to stay in the game," he said. "That really didn't affect me mentally or physically. I was able to continue to make pitches just as if nothing happened. It was just a mistake, and I paid for it."

Garcia also lost to the Reds at home July 28, giving up three runs over six innings in a 4-0 defeat. Prior to this year, he had been 10-2 with a 2.97 ERA in 14 career starts against Cincinnati.

The left-hander is 4-2 with a 1.84 ERA in eight starts at Busch Stadium this season.

Cincinnati's John Lamb (1-3, 5.35) has been shaky through his first seven career starts and comes off the shortest one yet, giving up three runs over four innings in a 9-8, 10-inning win at San Francisco on Tuesday. He limited the Cardinals to three hits over five innings in his last matchup, though he also walked six.

The Reds (63-85) have split the first six of this trip after stops in San Francisco and Milwaukee. Their starting pitching continues to be terrible with the rotation posting a 6.35 ERA over the last seven games. Anthony DeSclafani turned in the latest letdown, giving up five runs over 4 1-3 innings in an 8-4 loss to Milwaukee on Sunday.

Joey Votto has been locked in against Garcia this year, going 4 for 4 with a home run, double and two walks. He's hitting .227 over his last eight games but still owns a .486 on-base percentage in that span, largely thanks to 12 walks.

He walked twice Sunday to push his season total to 135 and match his own team record and has reached base in 37 straight games, four shy of his career high.