KISSIMMEE, Fla. -- The Astros nailed down what their shortstop position will look like entering the regular season on a whirlwind Sunday morning that saw Tyler Greene, who came to camp battling to win a job, out of work, and Ronny Cedeno wearing a Houston uniform.

Houston also optioned outfielder J.D. Martinez to Triple-A Oklahoma City and reassigned catcher Jason Jaramillo to Minor League camp. The team now has 34 players remaining in camp.

As MLB.com first reported Saturday, the Astros struck a deal with Cedeno and put him straight to work, starting him at shortstop on Sunday against the Marlins. He went 1-for-2 with a triple in the Astros' 4-1 win over the Marlins. Astros general manager Jeff Luhnow said the club informed Greene on Saturday he wasn't going to make the team.

The Astros will try to work out a trade with Greene, who is out of options. Greene was beat out by Marwin Gonzalez, but the Astros signed Cedeno to platoon at the position and provide some veteran leadership with Gonzalez and second baseman Jose Altuve.

"I'm very excited to be here," Cedeno said. "I can be an everyday player and that's very important. It's kind of frustrating because I got released in St. Louis but they pushed me to get here and I have an opportunity, so now I'm going to enjoy it the best I can."

Luhnow pursued Cedeno in the offseason, but wasn't aggressive considering he had Jed Lowrie in the fold. Lowrie was traded to Oakland last month.

"When [Cedeno] became available, we went back to our original plan," Luhnow said. "He sees an opportunity here to be, if not an every day [player], a guy that gets a lot of playing time. Ronny has a lot of experience at the big league level. He's only 30 years old, but he plays winter ball just about every year. I've been following his career since he was a prospect with the Cubs.

"He is defensively very, very good and with our young pitching staff, our ground-ball staff, we felt we needed a reliable defensive player that could help the pitchers. The last thing we want to do is extend innings by not being able to make plays. Ronny is also a Major League hitter, and I think he's going to give us an opportunity to produce some runs from that position as well."

Astros manager Bo Porter wouldn't commit to how he will split the playing time.

"I pretty much told [Cedeno] the same thing I told Tyler Greene and Marwin Gonzalez," he said. "We're waiting for somebody to take the bull by the horns. It's an opportunity at shortstop in this organization and somebody is going to have to prove to the staff they can play every day."

Greene, 29, was acquired by the Astros from the Cardinals on waivers last year, and he hit .246 with seven homers and 11 RBIs in 39 games for Houston. He struggled mightily this spring, and Gonzalez, a switch-hitter who plays other positions, proved to be more valuable.

"Tyler did a good job for us last year as part of this team," Luhnow said. "He's got value. He's a Major League player and I think it's more the emergence of Marwin, feeling that after Marwin spent all year with the club last year and the things he's been able to show us this spring, being a switch-hitter, being very solid defensively, being able to play third base, second base, shortstop. I think all of that led us to feel Marwin beat out Tyler for a position on the team."

The Astros traded Lowrie in February and came to camp with Greene and Gonzalez vying to be his replacement. They both had 42 at-bats in 18 games this spring, and Greene is hitting .167 with no RBIs and Gonzalez is hitting .238 with a homer and two RBIs.

"We felt we gave them both plenty of at-bats, plenty of opportunities to step up this spring," Luhnow said. "When you have a new staff that has no history with these players, we have some members of our staff that were here last year and we had a meeting upstairs and everybody spoke their minds. Unfortunately for Tyler, he did not have a good spring and that works against him, especially when the staff if relatively new. He's an established Major League player and I'm sure he's going to continue to have a good career."

Cedeno played for the Mets last year and appeared in 78 games, hitting .259 with four homers and 22 RBIs in 186 plate appearances. He's a career .247 hitter with 37 homers and 218 RBIs in an eight-year career with the Cubs, Pirates, Mariners and Mets.

Cedeno had been working out since he was released as he looked for another opportunity.

"There's a lot of young guys here, and that's what I'm here for, just trying to help the guys, too, and keep everything together," he said. "Communication is very important on the field. That's the key -- where [Altuve] likes the ball during double plays and how we're going to play hitters. I think it's going to help."