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05/27/12 8:59 PM ET

Walk-off losses not a concern for Mills

LOS ANGELES -- The sight of an opposing team celebrating a walk-off win on its home field has become all too familiar for Astros manager Brad Mills this season.

Five of Houston's 14 road losses heading into Sunday's series finale against the Dodgers have come in the final at-bat. The most recent episode came Saturday, when Los Angeles catcher A.J. Ellis cranked a three-run homer in the ninth inning.

The losses may be deflating, but Mills is choosing to look at them in a more positive light.

"What does a walk-off loss mean -- No. 1, it means you were in the game all the way until the end," Mills said. "And that's what we want. We want to give ourselves a chance to win games and keep battling all the way until the end."

The Astros have been able to stay in games, but they haven't been able to win those tight contests on the road, posting a 2-8 mark in one-run road games. At home, they're 6-0 in such contests.

Mills emphasized his belief that those stats are purely the results of over-analysis and that they'd even out as the season goes on.

"Whether it's a mental thing or what, more than anything else, we're in that game and giving ourselves a chance to win games, and it's going to happen," Mills said. "These players are too good. We're going to get those hits and we're going to drive those runs in."

Abad placed on DL, Cedeno called up

LOS ANGELES -- Just when it seemed as though Fernando Abad was turning a corner this season, the Astros lefty reliever was placed on the 15-day disabled list with a right intercostal strain.

To replace Abad, the Astros purchased the contract of Xavier Cedeno from Triple-A Oklahoma City, and he'll be available for the club's series finale in Los Angeles on Sunday. The move fills out Houston's 40-man roster.

Abad pitched on Friday and then felt tenderness in his right side afterward that caused him discomfort. After meeting with the training staff again on Saturday, the decision was made to place him on the DL.

"I didn't feel anything before I got in the game, and during the game I didn't feel anything, too," Abad said. "After that, I don't know what happened."

In 15 appearances this season, Abad has a 5.00 ERA. In his past eight outings, however, he has surrendered just one run.

Manager Brad Mills sees the 25-year-old Cedeno, also a lefty reliever, as an adequate replacement for Abad. In 17 appearances with Oklahoma City, Cedeno is 2-0 with an ERA of 0.42. Left-handed hitters are just 1-for-24 against him.

"Because of the way he's pitching, he'll go right into the role that Abad had, and step right in there," Mills said.

That said, Mills noted the loss of Abad is a blow to a bullpen that has been sharp for most of the season. In Abad's last appearance, he recorded a crucial eighth-inning strikeout of James Loney to preserve a Houston victory.

But Mills had to dip into his bullpen early on Saturday night, and with a doubleheader on Monday, he didn't want to be left short-handed in relief.

"It's too bad," Mills said. "Any time you have somebody that's throwing the ball well and you're going to have to do without him for a couple of weeks, that's difficult."

In a brief big league stint last season, Cedeno allowed five runs in just 1 2/3 innings. Mills said not to look too far into that, because the club called Cedeno up in September from his home in Puerto Rico.

Cedeno, whose Minor League season had ended two weeks earlier, came to the big leagues cold, and the ensuing struggles were a result of that, Mills said.

Lyles to start Game 2 of Monday's twin bill

LOS ANGELES -- Jordan Lyles will start for the Astros in the second game of Monday's scheduled doubleheader at Coors Field, manager Brad Mills announced after Sunday's game in Los Angeles.

The move comes as no surprise, as Lyles started Thursday for Triple-A Oklahoma City and was removed after just two innings.

It will be the fourth start of the season for the 21-year-old right-hander. He's 0-1 with a 5.29 ERA. In his most recent start, Lyles allowed six earned runs in five innings against Texas.

Earlier on Sunday, Mills confirmed that lefty ace Wandy Rodriguez (4-4, 2.14 ERA) would get the ball in Game 1 of the twin bill against the Rockies' Juan Nicasio. Lyles will face Alex White in the nightcap.

A new rule this season allows for a 26-man roster on doubleheaders scheduled more than one day in advance. That means Lyles' callup will be only temporary.

"I'd like to have the 26-man rule all the time," Mills kidded. "But yeah, it's real good, definitely for a doubleheader like this."

Still, it might not be long before Lyles is back again. The club will eventually have to make a decision on a starter for their game next Sunday against Cincinnati, which would fall on Lyles' turn in the rotation.

AJ Cassavell is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.