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7/28/2014 8:00 P.M. ET

Astros' rotation depth offers trade options

HOUSTON -- In effort to land a bat to add to their struggling offense, the Astros are willing to trade one of their starting pitchers.

The Astros have six healthy starting pitchers when you include right-hander Brad Peacock, who was recently sent to Triple-A Oklahoma City after a pair of shaky outings. That leaves right-handers Scott Feldman, Jarred Cosart and Collin McHugh and left-handers Dallas Keuchel Brett Oberholtzer, though Feldman's three-year, $30-million deal makes him difficult to move.

Houston general manager Jeff Luhnow indicated Monday no deals were in the works. The non-waiver Trade Deadline is Thursday.

"Our offense has been struggling, so as we have conversations, we'll explore options that might give us some help offensively," Luhnow said.

The Astros, who have scored six runs in their previous four games, are especially thin in the outfield, where Dexter Fowler (intercostal strain), George Springer (quad strain) and Alex Presley (oblique strain) are all on the 15-day disabled and not expected to return until Thursday.

"It's absolutely a concern," Luhnow said. "The best thing we can do for the Trade Deadline is to get Fowler, Springer and Presley back healthy. That could be an unbelievable coup for us. Hopefully, they're not too far away."

Astros interested in Cuban OF Castillo

HOUSTON -- The Astros may schedule a one-on-one workout with Cuban outfield prospect Rusney Castillo, general manager Jeff Luhnow said Monday.

Houston sent a scout to watch Castillo put on a show during his tryout in front of Major League scouts and executives on Saturday in Miami, and Luhnow said the club has an interest in signing him.

"He's definitely an interesting player," he said.

Castillo, 5-foot-9, 200 pounds, participated in live batting practice, threw from the outfield and fielded grounders at shortstop in front of representatives from 28 of 30 teams at the University of Miami. He's known for his speed and athleticism and likely will start the season in the Minor Leagues when he signs, but there's a belief that he could be in the big leagues by the end of this season and compete for a starting job next Spring Training.

Castillo, who left Cuba six months ago, established residency in Haiti and was cleared by the U.S. government to sign with a team earlier this month. He is represented by Roc Nation Sports, a joint venture between Roc Nation and CAA Sports.

"An international free agent who does not count toward the pool allotment is going to be sought after," Luhnow said. "The recent success of some of the higher-profile Cuban players -- [Yoenis] Cespedes, [Yasiel] Puig, [Jose] Abreu -- put this guy in a pretty good spot. He's a little different player from those guys, but he'll have a good market. We'll expect it to be competitive."

The Astros made a strong run at Abreu, and earlier this year offered Japanese pitcher Masahiro Tanaka a contract of at least $100 million.

"Eventually, we'll get our guy," Luhnow said. "We're doing it to sign guys, but we want to make sure we do it in a responsible way."

Singleton working to shorten his swing

HOUSTON -- Astros first baseman Jon Singleton and outfielder L.J. Hoes did some extensive work in the batting cage on the field Monday with hitting coach John Mallee. Singleton is hitting .178 with seven homers and 24 RBIs in 163 at-bats since he was called up and signed to contract.

"I'm trying to get the big-muscle-bodyness out of his swing and trying to get him more direct to the ball, shorten his path," Mallee said. "He's been overswinging and hitting long. We came out and did some tee work on the field and some flips and some high-velocity short pitch to where the ball is on him almost at the same reaction time as it is the game."

Mallee called the results "absolutely amazing" and said now it's a matter of Singleton trusting it enough to use in games.

"I'm trying to get better each and every day," Singleton said. "I'm trying to make small adjustments and trying to adjust to what they throw me and stuff like that and trying to time the ball better. Nothing too major. Just daily adjustments."

Mallee said he's going to get the struggling Hoes to stay behind the ball and drive it more.

"He's gets a little to his front side and his posture, his head is more forward as opposed to the center of his body or a little behind," Mallee said. "Trying to get him to lead out with his hip, and that allows him to be direct the ball and also get the barrel under his hands at contact and get left to the ball."

Brian McTaggart is reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.