KISSIMMEE, Fla. -- Versatile infielder Angel Sanchez has been dealing with a tight back this spring after slipping and falling while taking his mother's luggage down a set of stairs earlier this month. Sanchez took some ground balls hit right at him Wednesday and swung at balls on a tee.

"It felt way better than [Tuesday], so it's improving," he said.

Sanchez, a non-roster invitee who started at shortstop on Opening Day last year, was able to field ground balls at shortstop, second base and third base, but not at full speed. Houston manager Brad Mills would like to be able to get him on the field soon at full speed.

"His back is still real tight and the doctors don't feel comfortable letting him go with it," he said. "We're still taking nice and easy ground balls right at him, but it's putting him behind the eight ball because it's not giving him an opportunity to take ground balls and take swings. We're not going to rush him because we want to make sure he's 100 percent."

Sanchez hit .240 with 10 doubles and 28 RBIs last year, making 41 starts at shortstop, 14 at second base and eight at third base.

Wandy favorite for Opening Day start

KISSIMMEE, Fla. -- The Astros have yet to name an Opening Day starter, but all signs point toward veteran left-hander Wandy Rodriguez being on the mound when Houston faces the Colorado Rockies on April 6 at Minute Maid Park. Houston hasn't had a lefty start on Opening Day since Dave Roberts in 1974.

With Brett Myers -- last year's Opening Day starter -- being moved into the closer role, Rodriguez is the most accomplished member of the Astros starting rotation. He's entering his eighth year in Houston's rotation and ranks third on the team's all-time charts among wins by a left-hander and first for strikeouts by a lefty.

"We're dealing with the situation with his back tightness and so forth right now, and we're hoping to be able to get that all taken care of so we don't have to worry about that," Astros manager Brad Mills said. "He's got to be considered very heavily."

Rodriguez said he would be honored if he was asked by Mills to start Opening Day.

"That would be great," he said. "Every game is important, but everybody wants to start Opening Day."

Rotation may be heavy on southpaws

KISSIMMEE, Fla. -- It's possible the Astros could begin the regular season with three left-handers in their starting rotation. Wandy Rodriguez is a lock to be in the rotation if he's not traded, and J.A. Happ has an inside track for another rotation spot. Non-roster invitee Zach Duke will be used in relief and a starter this spring and could crack the rotation.

"I don't think I would mind it, especially against some ball clubs," said Astros manager Brad Mills when asked about carrying three lefties in the rotation. "A lot of times people look at Minute Maid Park and don't think it's real conducive to having a whole lot of lefties in your rotation, but at the same time if they're quality lefties and the best pitchers you have, that's fine with me. I have no problems with that at all."

Duke threw a pair of 20-pitch sessions to live hitters on Wednesday and is scheduled to follow starter Jordan Lyles to the mound Monday against the Braves. Mills said Duke will likely start the game the next time their turn in the rotation comes up.

Duke has been used primarily as a starter in his career, but last year made 12 relief appearances from among his 21 games pitched for the Arizona Diamondbacks.

"He's thrown the ball very well," Mills said.

Ruggiano battling for spot

KISSIMMEE, Fla. -- Justin Ruggiano grew up in Austin, but he wasn't exactly a fan of the Astros.

"I was a Nolan Ryan fan," said Ruggiano, a non-roster outfielder battling for a roster spot. "Originally I was watching the Astros and then he made the switch to the Rangers. That was the guy I really looked up to. It wasn't a team thing. But I went to more Astros games than Rangers games."

Ruggiano, 29, has a chance to be only the second product of Texas A&M to ever play for the Astros in a Major League game, joining Mark Ross (1982-85), who's now Houston's west coast scouting supervisor. Ruggiano appeared in 46 games last year for the Tampa Bay Rays.

"I don't like to speculate as to who the manager is going to want or who the club is going to go with," he said. "I'm hoping I get the opportunity to play and let the play on the field take care of itself and indicate who makes the team."

Ruggiano can play all three outfield positions, but has played more in left field than any other position in his 98-game Major League career. The chance to make the club out of spring camp would be unbelievable, he said.

"It's something I've been looking to accomplish my whole career," he said. "I haven't been on an Opening Day roster. I've been called up quite a bit, but never been on the roster Opening Day."

Worth noting

Astros general manager Jeff Luhnow will be away from camp for a couple of days to speak at the MIT Sloan Sports Analytics Conference in Boston on Friday morning. The conference, co-chaired by Houston Rockets general manager Daryl Morey, provides a forum for industry professionals (executives and leading researchers) and students to discuss the increasing role of analytics in the sports industry.