The Astros switched up their rotation for Saturday, announcing after their 6-1 loss to the Mariners on Friday night that left-hander Brett Oberholtzer would be recalled from Triple-A Oklahoma City to start at Safeco Field.
Oberholtzer began the year in the Astros' rotation but went 0-6 with 5.68 ERA in seven starts. When Scott Feldman came off the disabled list, the lefty was sent to Oklahoma City, where he made two starts and was 1-1 with a 3.75 ERA.
Oberholtzer's start bumps left-hander Dallas Keuchel's next start to Sunday.
Keuchel threw a shutout May 13 against the Rangers and came within a strike of throwing another one Monday before manager Bo Porter removed him after 8 2/3 innings. He threw 128 pitches Monday after throwing 108 in his win against Texas.
Porter said he wanted all of his starters to get an extra day of rest. They will get another extra day when Brad Peacock, who was scratched from his start Friday with right forearm soreness, is moved back into the rotation.
"You look at our starting pitching, and that's been one of our strong suits of our team this year," Porter said. "We want to do everything we can to take care of those guys."
Mariners: Maurer's rotation spot in danger
With left-hander James Paxton making a rehab start with Triple-A Tacoma on Saturday, Brandon Maurer's days in the starting rotation may be numbered.
The 23-year-old will get the start Saturday against the Astros, but he may only have one or two more chances to improve his subpar numbers.
In five starts, the right-hander is 1-2 with a 6.00 ERA. Before Paxton was sidelined by a lat strain April 8, he racked up a 2-0 record and a 2.25 ERA.
Maurer's struggles have been magnified in Safeco Field. Despite the stadium's reputation as a pitcher's park, Maurer is 0-2 with a 6.75 ERA at home.
The Mariners have not said what changes will be made when Paxton returns, but assuming Paxton's rehab outings go well, Maurer may be looking at time in the bullpen or in the Minor Leagues.
Astros: Altuve leading charge on offense
Jose Altuve is making a strong push for his second All-Star Game berth in three years.
The 24-year-old second baseman went 3-for-4 on Friday and has hit safely in 14 of his last 15 games -- including 10 multi-hit games during that stretch.
In those 15 games, Altuve is hitting .418 with 10 runs scored, seven doubles, one triple, one home run, six RBIs, two walks and four steals. On Friday, he took the Major League lead with 66 hits and is first in the American League with 17 steals.
He has driven in the only two runs the Astros have scored in the first two games of their series against the Mariners.
"He continues to have an All-Star season and play the best baseball of his life," Porter said. "It's a credit to the effort and the commitment in which he made this offseason, getting himself ready for this season.
"It's rewarding to see a guy put that kind of effort into it and have the type of success in which he's enjoying right now."
• Astros center fielder Dexter Fowler has reached base safely in 20 of 21 games in May, hitting .303 in the month and scoring 12 runs.
• Over the last 11 games, the Astros' bullpen has a 1.23 ERA and is holding opponents to a .211 batting average.
• Mariners catcher Mike Zunino's two hits Friday gave him his first multi-hit game since May 2 in Houston.
Adam Lichtenstein is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.