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.