The St. Louis Cardinals somehow aren't out of it in the race for a National League playoff spot with just 18 games left in the 2026 Major League Baseball regular season. Because of that, each series from here on out is even more important than it would've been if the Cardinals were out of the mix, especially against teams that St. Louis should beat. For example, the Cardinals will kick off a three-game series against the San Francisco Giants on Monday night on the road. The Giants are 59-85 on the season. St. Louis is 72-72 on the season and should have a good chance to come out on top. The Cardinals are four games out of a playoff spot right now. With so few games remaining in the regular season, St. Louis can't afford to drop much below that. Here are the Cardinals' probable starters for the must-win Giants series. Monday — Michael McGreevySep 1, 2026; Los Angeles, California, USA; St. Louis Cardinals pitcher Michael McGreevy (36) pitches during the fifth inning against the Los Angeles Dodgers at Dodger Stadium. Mandatory Credit: Kirby Lee-Imagn Images | IMAGN IMAGES via Reuters ConnectMichael McGreevy is scheduled to take the hill on Monday night to kick off the three-game series. The Cardinals are going to need McGreevy to turn it around because he hasn't quite looked like himself since the end of July. McGreevy was the Cardinals' most consistent starter for most of the season, but he has struggled in his last seven starts to the tune of a 7.09 ERA. The Cardinals need more from McGreevy down the stretch if they want to have a chance to make a run at a playoff spot. Tuesday — Quinn Mathews Sep 3, 2026; Los Angeles, California, USA; St. Louis Cardinals starting pitcher Quinn Mathews (60) throws a pitch against the Los Angeles Dodgers during the first inning at Dodger Stadium. Mandatory Credit: Kirby Lee-Imagn Images | IMAGN IMAGES via Reuters ConnectMathews has five starts under his belt in the majors and four of them have been great, including his last time out on Sep. 3 against the Los Angeles Dodgers. The lefty tossed five innings and allowed just one run. Overall, Mathews has looked the part since being promoted from Triple-A. In his five starts, he's allowed more than two runs just one time. The Cardinals are going need him to keep it up down the stretch. He has quickly gone from Triple-A to integral to the big league club. Wednesday — TBDSep 5, 2023; Atlanta, Georgia, USA; A detailed view of the hat and glove of St. Louis Cardinals second baseman Nolan Gorman (not pictured) before a game against the Atlanta Braves at Truist Park. Mandatory Credit: Brett Davis-USA TODAY Sports | USA TODAY Sports via Reuters ConnectThe Cardinals' starter for Wednesday is still up in the air. Andre Pallante made his last start on Sep. 4. So, he appears to be the most likely option for the series finale, unless the Cardinals want to give extra time between starts. If Pallante isn't the guy here, it wouldn't be shocking to see another bullpen day for St. Louis. Add us as a preferred source on GoogleFollow