HOUSTON -- The Astros made an expected roster move following Saturday's loss to the Reds when they called up right-handed pitcher Jordan Lyles to start Sunday's series finale at Minute Maid Park, but the corresponding move was surprising.

The club announced it was optioning infielder Matt Downs to Triple-A Oklahoma City to make room for Lyles. Downs, who had a pair of hits Saturday, was hitting .169 in 71 at-bats with three homers and six RBIs and had been getting spotty starts, but his versatility and power stroke made him a valuable asset.

Downs spent all of last season on the Major League roster and had a bang-up season, hitting .276 with 10 homers and 41 RBIs in only 199 at-bats. He was also baseball's best pinch-hitter a year ago, leading the Majors in pinch-hits (15) and pinch-hit on-base percentage (.462).

Lyles has bounced between Houston and Oklahoma City this year, going 0-1 with a 5.73 ERA in four starts with the Astros. The Astros have used their off days to try to spread their starts between four pitchers, calling up Lyles when a fifth starter is needed.

Mills concerned about Lee's hamstring injury

HOUSTON -- Astros first baseman Carlos Lee, who left Friday's loss to the Reds with a strained left hamstring, wasn't in the lineup Saturday and is likely out until at least Tuesday. Astros manager Brad Mills expressed concern about Lee's health and said Saturday he would be out "for a minimum of a couple of days anyway."

Mills observed Saturday as Lee was put through some tests by the medical staff to gauge the extent of the injury. Matt Downs started at first base in place of Lee, who is hitting .297 with four homers and 23 RBIs this season.

"He has point tenderness," Mills said. "We're going to evaluate that moving forward as he gets treatment. We're going to kind of monitor him. It's tender and sore. That's all I'm really prepared to say. We don't think there's a tear or something, but at the same time we want to check things out."

Astros general manager Jeff Luhnow took time away from his Draft preparation Saturday to go to the home clubhouse during batting practice and check up on Lee.

"Clearly, when you lose a productive hitter like that, even just for a few days, it's going to affect us," Luhnow said. "Those are the types of injuries that you may not know right away how long he's going to be out, but if it reaches a point where we think he's going to be out more than a week, then certainly we would consider making a move."

Astros may pursue Cuban outfielder Soler

HOUSTON -- Astros general manager Jeff Luhnow said Saturday the club is considering pursuing Cuban corner outfielder Jorge Soler, who was declared a free agent Saturday and is expected to sign with a club in the next few weeks.

"It would be safe to say that we're looking into it," Luhnow said. "We like the player, and it's just a matter of how much competition there is going to be and where it's going to end up, but we're definitely looking into it."

Soler must sign with a Major League club before July 2 or he will be subject to new CBA guidelines that will limit spending on international prospects to $2.9 million per team without penalty. Luhnow expects the signing process to happen quickly.

"It's a milestone that all 30 clubs have been waiting for," he said. "Now that there's an opportunity to engage his representatives and figure out what they're looking for, I think it's going to be a fairly quick process. We're aware of what's happening and we're going to be involved to the extent it would make sense for us."

Soler applied for residency in the Dominican Republic earlier this year -- the first step to becoming eligible for free agency -- and was declared a free agent by Major League Baseball on Saturday. All players who are declared free agents must still be legally cleared by the U.S. Treasury Department's Office of Foreign Assets Control before they can sign a contract.