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(SportsNetwork.com) - Seeing Adam Wainwright on the mound is probably enough to make a lot of hitter's stomachs turn, but it is the St. Louis Cardinals who are the ones battling illness.

Wainwright looks to secure his second career 20-win season, but does so in the opener of a three-game set on Monday against the Chicago Cubs with a number of ill teammates behind him.

The right-handed Wainwright is second in baseball with 19 wins, trailing only Clayton Kershaw of the Los Angeles Dodgers and his 20 victories. Wainwright is looking to join Kershaw at 20 wins, a number he hasn't reached since a 20-11 campaign in 2010.

Wainwright has won four straight starts and is coming off his third shutout of the season and ninth of his career as he blanked Milwaukee 2-0 on Wednesday. The 33-year-old scattered seven hits and two walks while striking out seven, moving to 19-9 with a 2.45 earned run average on the year.

"I would say that was an impressive pitching performance," St. Louis manager Mike Matheny said. "He had everything and then when you watch the ninth and see 95 (mph) pop up there and you realize that this guy still had a lot in the tank."

Wainwright has allowed only two runs over his past three outings and is 2-1 this season against the Cubs with a 4.32 ERA in four starts.

Support could be limited tonight for Wainwright as a stomach bug is impacting the Cardinals. They dropped a 7-2 decision to the Cincinnati Reds on Sunday in a game in which Matheny estimated more than 10 players were unavailable or impacted by the illness.

"It's just something that we have to wade through. Guys are still kind of popping up (sick), even mid-game," said Matheny afterwards. "There are some other guys we weren't expecting for it to hit and it did, so we're just going to have to try and get through it and weather the storm."

St. Louis, which had a four-game winning streak snapped, took the field last night having already clinched at least a playoff spot thanks to Pittsburgh's victory over Milwaukee earlier in the day, and the Cardinals lead the Pirates by 2 1/2 games for first place in the National League Central.

The Cards have six games left in the regular season to the Pirates' seven, with a magic number of five to clinch the division.

The Cubs, meanwhile, lost three of four to the Los Angeles Dodgers over the weekend, falling 8-5 in Sunday's finale as starter Jacob Turner allowed five runs -- four earned -- over five innings of work.

"We fell behind early a few games and we keep coming back and fighting," said Cubs manager Rick Renteria.

Travis Wood draws the start for the Cubs tonight and has been effective in four starts this season against the Cardinals, going 2-0 with a 3.97 ERA.

The left-hander's previous start came last Monday versus Cincinnati and he did not factor into a 1-0 win, giving up three hits and walking three over six scoreless innings.

Wood is 8-12 with a 4.86 ERA on the year and can match the career-high nine games he won last season, when he had a 3.11 ERA over 32 starts.

The Cardinals are 9-7 against the Cubs this season.