KISSIMMEE, Fla. -- Lucas Harrell is trying to pitch himself into the race for the No. 5 spot in the Astros' rotation.
He's doing a pretty good job.
Harrell gave up three singles an unearned run over five innings in his first start of spring training, helping Houston beat the Florida Marlins 6-3 Wednesday.
"I feel like there's still a few guys ahead of me," the 26-year-old Harrell said. "I didn't really pitch well at the beginning of spring, but hopefully I can finish strong and put something in their heads. Hopefully I can make a push to make this team."
Harrell started in Bud Norris' spot because Norris experienced tightness in his triceps, moving his next start back to Sunday. Harrell is still in the competition with Jordan Lyles and Kyle Weiland for the Astros' No. 5 pitching spot.
"We're kind of wading through a few issues as we move into this last week," manager Brad Mills said.
Harrell outdueled Carlos Zambrano, who gave up five hits and five walks in four innings for the Marlins.
Harrell walked none and 11 of his 15 outs came on groundballs, an indication that his sinker was effective.
"In my last couple of outings, I wasn't getting a lot of groundballs because my arm angle was a little high," he said. "I wanted to make sure I got the right arm slot to get that sinker going, get some groundballs."
Houston shortstop Jed Lowrie left the game in the third inning with a sprained right thumb after getting picked off second game. X-rays were negative.
Lowrie's fine spring (.333 with two home runs in 14 games) has been marred by a painful foul tip off his right foot, a pitch off his left leg and now the thumb injury.
"Hopefully it's ice a couple days and I'm back out there. That's ideal," he said. "I'm going to go with that until they tell me otherwise."
Omar Infante had two of Miami's hits and scored twice. ... Astros center fielder Jordan Schafer returned from Atlanta where he had his sprained left hand examined. Schafer expects to play by Sunday. ... Astros outfielder Justin Ruggiano was in Austin, Tex., where his wife gave birth to a girl . . . In 17 2/3 g innings, Zambrano has 18 strikeouts and 14 walks. ... Utilityman Brian Bixler, who hit three home runs this spring, and Angel Sanchez, last year's opening-day shortstop, were among five players optioned or reassigned to the minors Wednesday, reducing Houston's roster to 34 players.