Brushing aside an ongoing issue with a blister on the middle finger of his pitching hand, Hisashi Iwakuma has been one of the best pitchers in the American League through his first four starts this season.
While Mariners manager Eric Wedge has kept Iwakuma from tossing more than 90 pitches in any of his starts, the right-hander has still managed to post a 2-0 record and 1.69 ERA, with opposing batters hitting just .135.
"He's been pretty efficient, but almost all his games we'd have sent him out there at least another inning. I think we've managed him pretty good, just to keep him in the rotation," Wedge said. "And obviously he's pitching very well."
Iwakuma will look to keep his hot streak going on Tuesday as the Mariners square off against the Astros at Minute Maid Park.
A former Japanese professional who joined the Mariners last season, Iwakuma will be making his first career appearance against the Astros.
Meanwhile, Bud Norris will be on the hill for Houston, ready to rebound after the shortest start of his career.
Lasting just two-thirds of an inning on Wednesday against the Oakland A's, Norris allowed six runs on five hits. Struggling with his command during the outing, he walked three and was unable to record a strikeout,falling to 2-2 on the season with a 4.74 ERA.
"I don't know what to say. I felt good, but they were finding holes," Norris said after the game. "I was trying to battle through it and keep making pitches. Unfortunately, it wasn't my day. They swung the bats and found some holes. I just have to keep making pitches."
That type of performance has been a trend for the Astros so far this season. Houston's rotation has only four quality starts in 19 games and has lost eight of its past nine contests.
"You always want your starters to keep you in the game, and that is the formula for saving the bullpen," Astros manager Bo Porter said. "You don't want to depend on [long relievers] to save your bullpen. You want your starters to go deep into the game, go seven or eight innings, and allow that to save your bullpen."
Mariners: Saunders plays catch
Outfielder Michael Saunders played some light catch on Monday for the first time since going on the 15-day disabled list with a sprained right shoulder.
Saunders is eligible to come off the DL on Friday, but Wedge said that return date remains up in the air.
"I'm not prepared to say that just yet," Wedge said. "We need to let him play catch a couple more days and go from there, decide how we're going to play this out."
Astros: Cisnero recalled
Houston recalled right-hander Jose Cisnero from Triple-A Oklahoma City on Monday and optioned left-hander Brett Oberholtzer back down after a brief stay on the Major League roster.
With the Astros looking to have fresh arms in the bullpen that can work multiple innings, Cisnero got right to work in Monday's game, allowing just two hits in 3 2/3 innings of work.
"It's my first time in the big leagues, and I'm excited," Cisnero said before the game.
• Mariners center fielder Franklin Gutierrez returned to the starting lineup after sitting out Sunday, but played just four innings before getting hurt diving for a shallow fly ball. The Mariners said Gutierrez has a tight right hamstring and will be re-evaluated on Tuesday.
• Astros right-hander Josh Fields threw 30 pitches in the bullpen Monday in Kissimmee, Fla., at about 90 percent intensity. He's increasing his intensity every session and will be facing live hitters for the first time in a few days.
Quinn Roberts is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.