KISSIMMEE, Fla. -- J.D. Martinez, who had a terrific first month in the Major Leagues after being called up from Double-A the day after Hunter Pence was traded in 2011, saw his tenure with the Astros come to an end Saturday.

The Astros released the 26-year-old outfielder, who had struggled to get on track offensively this spring without routine playing time. The team also announced it had optioned left-hander Darin Downs to Triple-A and reassigned first baseman Japhet Amador and infielder Gregorio Petit to Triple-A.

As Martinez packed up his things in the Osceola County Stadium clubhouse early Saturday, a steady stream of teammates came over and exchanged hugs, handshakes and well-wishes.

"It's all right," Martinez said. "I'm not really down about it. It is what it is. Obviously, Houston is the team that brought me up and where I want to be. Everything happens for a reason."

Martinez, who was vying for a spot in left or right field, hit .167 with one RBI in 18 at-bats this spring. He was taken off the 40-man roster prior to camp, and the Astros have younger players like L.J. Hoes, Robbie Grossman and top prospect George Springer competing for playing time in the outfield as well.

"We had a lot of history with J.D., and he's got some value as a right-handed power hitter, outfielder," Astros general manager Jeff Luhnow said. "We really feel like -- to a certain extent -- we're a victim of our own success. As we continue to develop young talent, we're going to end up not having room for some players who fit in in the past and could fit in with other clubs. We wish him the best. We still think he's a Major League player. It's just not a fit for our club right now."

Martinez spent parts of three years in the Major Leagues with the Astros, hitting .251 with 24 homers and 126 RBIs. His best year was his rookie season of 2011 when he hit .274 with six homers and 35 RBIs -- and started 52 of the final 55 games after being called up on July 29 to replace Pence in the lineup.

He drove in 28 runs in August 2011, which ranked second in the National League and set an Astros' rookie record for any month.

"Obviously, I'm sad to leave Houston," he said. "I love the fans and players and everyone here. I feel like they have a lot of guys coming up, and if there's not room for me to get at-bats and not room for me to play, it's best to let me go and not try to hold me back, and I commend them for that and I thank them for that."

Martinez knew he had to play winter ball to post some numbers. He batted .312 with six homers and 18 RBIs in 24 games in Venezuela last offseason. The experience was a good one, even though he lost 16 pounds because of sickness.

Still, with Springer and Hoes getting time in right field, Martinez's at-bats were limited this spring.

"I feel that it was very tough, given my situation of how I was going into games and stuff," he said. "I know how it works. I know in Venezuela I hit the ball really well down there. Let's say I have a new respect for guys who come off the bench every day. That's not easy to do."

Martinez hopes to be able to land with another team.

"Jeff was telling [me] there's a lot of teams that were looking around," he said. "I was supposed to make a lot of money in Triple-A, and because of that it's kind of spooked teams away. Now it will be a lot easier to get picked up."