• Texas title tussle: HOU @ TEX, 8:05 p.m ET
This is one the most important (if not the most important) Rangers-Astros series in recent memory, as the teams are both in the thick of the AL West chase. Collin McHugh will try to help Houston hold onto the lead it has held for most of the season, and the righty is looking to win his fourth consecutive start. Texas' Martin Perez, 3-1 with a 2.17 ERA lifetime against the Astros, has lost his last two starts.
• Cleveland's coming: KC @ CLE, 7:10 p.m. ET
The AL Central is now home to two Wild Card hopefuls, with the Twins and Indians both chasing that second spot. Cleveland will have to get it done against the first-place Royals, who will have Kris Medlen on the mound. Josh Tomlin will make his seventh start of the season and first against the Royals.
• Can Martinez get his groove back?: STL @ MIL, 8:10 p.m. ET
For the majority of the season, Cardinals right-hander Carlos Martinez was one of the top starters in the NL. But he's allowed three or more runs in each of his last eight starts and has pitched past the fifth inning in just three of those games. In an effort to get his groove back, he'll take the mound against the Brewers -- against whom he threw seven scoreless innings on April 24.
• Hughes returns: DET @ MIN, 8:10 p.m. ET
The Twins are happy to welcome back right-hander Phil Hughes, who has been out since Aug. 9 with a lower back injury. He'll join the club in the middle of a Wild Card chase, and will likely be held to 75-80 pitches since he didn't make a rehab start. Alfredo Simon gets the ball for the Tigers looking to avenge his last outing against Minnesota, when he gave up seven runs on 10 hits in 2 1/3 innings at Target Field in July.
Joey Nowak is a reporter for MLB.com. Follow him on Twitter at @joeynowak. This story was not subject to the approval of Major League Baseball or its clubs.