Another injury hasn't prevented the St. Louis Cardinals from inching closer to another NL Central title.

After grinding out a victory in the opener of a critical three-game series with the Pittsburgh Pirates, the Cardinals can clinch their third consecutive division crown and first 100-win season since 2005 Tuesday night at PNC Park.

St. Louis (99-58) reduced its magic number to two with Monday's 3-0 win over the second-place Pirates, scoring all its runs in the ninth inning and overcoming 10 walks by its pitchers and a frightening injury to Stephen Piscotty. The rookie was carted off and spent the night at a local hospital for after a violent outfield collision with Peter Bourjos in the seventh.

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"I don't know if there is a game that would define it more than this one all season," manager Mike Matheny said. "We had our backs against the wall every single inning."

The Cardinals announced during the game that Piscotty sustained a bruise to his head when struck by Bourjos' left knee.

Piscotty's injury came on the same day St. Louis announced that catcher Yadier Molina will miss at least the rest of the regular season while recovering from a partially torn ligament in his left thumb.

The Cardinals did receive good news regarding ace Adam Wainwright, who could be available as a reliever as soon as Wednesday after successfully throwing a simulated game Monday. The three-time All-Star tore his left Achilles tendon April 25.

Pittsburgh (95-62) remained alive in the division race by winning eight straight prior to being one-hit in Sunday's 4-0 loss to the Chicago Cubs. It fell four games back with five to play, however, after stranding 16 runners and finishing 0 for 12 with men in scoring position.

The Pirates became the first team since Montreal in April 1982 to not score in a nine-inning game when drawing at least 10 walks.

"This was tough, because we gave the game away," outfielder Andrew McCutchen said. "A fluke, crazy - call it what you want. But for us not to get any runs with all the chances we had."

Pittsburgh's offense also has struggled in three previous 2015 matchups with Michael Wacha (17-6, 3.15 ERA), who's 2-0 with a 1.93 ERA and allowed two earned runs in six innings in an 8-5 win at PNC Park May 8.

Wacha hasn't been in top form of late, though, posting a 6.75 ERA while splitting his last four starts. He's walked 14 and surrendered five homers in 20 innings during the stretch.

The right-hander did earn his 17th win by holding Milwaukee to three runs in five innings Thursday.

McCutchen is 5 for 9 with a homer off Wacha this season but is hitting .160 over his last eight games.

The Pirates, now 3 1-2 games up on the Cubs for the first wild card after Chicago's win over Kansas City on Monday, put their division fortunes in the hands of Charlie Morton (9-8, 4.54) as he tries to end a lengthy winless drought against St. Louis.

Morton is 0-8 with a 4.76 ERA in 11 meetings with the Cardinals since a road win April 4, 2011. He did pitch well Sept. 9 in Busch Stadium, yielding one earned run and four hits in six innings of a 4-1 defeat.

The right-hander allowed six runs and 10 hits over 4 1-3 innings Wednesday at Colorado, six days after permitting five earned runs through five in a 9-6 home loss to the Cubs.

Mark Reynolds, who homered off Mark Melancon for the final two runs Monday, is 4 for 9 against Morton. Jon Jay, whose single in the ninth scored the initial run on Gregory Polanco's error, is 9 for 22.