Milwaukee right-hander Marco Estrada is scheduled to make his ninth start of the season in pursuit of his first win today, when the Brewers visit Minute Maid Park for the finale of a three-game series with the host Houston Astros.

But Estrada could step aside in favor of staff ace Zack Greinke, who started Saturday's game, but was ejected after only four pitches after spiking the ball after a close play at first base.

"I don't blame the umpire for what he did," Greinke said. "I didn't mean it toward him and I shouldn't have done that. I didn't think about it at the time and didn't think there was anything wrong with it."

Milwaukee manager Ron Roenicke said the team was considering bringing Greinke back for a second straight outing, but hadn't decided yet.

"We already talked to Zack. He thinks he would be fine, but we're not positive which way we're going to go," Roenicke said. "We've got some more conversations to go through."

For his sake, Greinke is on board with the idea.

"It'd be a shame to completely waste a day I should be pitching," he said.

If Milwaukee stays on schedule, Estrada will face the Astros for the sixth time in his career, but the first time as a starter.

He's split 2012 between starting and relieving, making eight starts and five bullpen appearances while allowing 42 hits and 23 runs in 48 innings.

In his last outing, on July 3, he was touched for two runs on four hits in six innings while getting a no-decision in the Brewers' wild 13-12 defeat of Miami.

Against Houston, he's allowed four runs on six hits in 4 2/3 relief innings.

The Astros counter with young righty Jordan Lyles, who'll try to rebound from a seven-run shelling against Pittsburgh in his last start.

On July 2 in Pittsburgh, the 21-year-old lasted just four innings while allowing nine hits and seven runs in an 11-2 loss to the Pirates.

One start earlier, he'd picked up his second win of the season against San Diego, while giving up just a run on six hits in 6 1/3 innings.

A 2008 supplemental draft pick, Lyles debuted with the Astros last season and won two times in 10 decisions over 20 appearances.

On Saturday, Jed Lowrie went 2-for-4 with an RBI and two runs scored as the Astros snapped a nine-game losing streak with a 6-3 win.

J.D. Martinez was 3-for-4 with a run scored, while Jason Castro added two RBI for the Astros, who last won a game on June 27 against San Diego.

Wandy Rodriguez (7-6) went 5 1/3 innings in the win, giving up two unearned runs on four hits with two walks and five strikeouts.

"There's a lot of good things that happened (Saturday) and Wandy came out of the chute throwing the ball extremely well," Astros manager Brad Mills said. "It was very good to see him pitch like that."

Cody Ransom drove in a run while Aramis Ramirez went 2-for-4 with a run scored for the Brewers, who had won five of seven coming in.

The Astros won three of the first five meetings between the teams in 2012, including a sweep of a two-game set at Houston on May 16-17.