ST. LOUIS -- The Astros are in the market for a new Class A affiliate.

Astros general manager Jeff Luhnow said Tuesday the team won't renew its player development contract with the Lexington Legends of the South Atlantic League. The Astros recently extended their player development contracts with Triple-A Oklahoma City and advanced Class A Lancaster.

"It looks like they've decided to explore other options," Luhnow said of Lexington. "That's fine with us. We're going to explore our options as well."

Class A teams that are without an affiliate include Quad Cities, Kane County, Cedar Rapids, Beloit, Burlington and Peoria, all in the Midwest League. All player development contracts must be signed by Oct. 7.

"We're in the process of figuring out what our top choices are and going after it," Luhnow said.

The Astros have been affiliated with Lexington since the franchise began play in 2001.

Wright nominated for Clemente Award

ST. LOUIS -- Relief pitcher Wesley Wright was named as the Astros' nominee for the Roberto Clemente Award, which recognizes a Major League Baseball player who best represents the game of baseball through positive contributions on and off the field, including sportsmanship and community involvement, on Tuesday.

"I think Roberto Clemente was a great player, as well as a great man, and he did a lot of great things on and off the field," Wright said. "I'm honored to be nominated and represent the Astros. Whether I win or not, it's still a great thing."

Fans are encouraged to participate in the process of selecting the national award recipient by visiting mlb.com/clementeaward to vote for one of the 30 nominees. Participating fans will be automatically registered for a chance to win a trip to the 2012 World Series, where the national winner of the Roberto Clemente Award presented by Chevrolet will be announced. Voting ends at 11:59 p.m. ET on Oct. 14, and the winner of the fan poll will receive one vote among those cast by a selection panel.

Wright said community involvement is vital.

"It's really important," he said. "I think it's probably our duty to do that. So many people come out and support us on a regular basis, and if you can give something back to the community it's well worth doing. I try to do it here in Houston as well as back home in Alabama."

The Roberto Clemente Award is named for the 15-time MLB All-Star and Hall of Famer who died in a plane crash on New Year's Eve 1972 while attempting to deliver supplies to earthquake victims in Nicaragua.

Gonzalez available off bench for Astros

ST. LOUIS -- Rookie shortstop Marwin Gonzalez, who hasn't played since injuring his left ankle on Aug. 30, was expected to return to action Tuesday, interim manager Tony DeFrancesco said.

"We're hoping Jed [Lowrie] can get us three or four at-bats and drill a ball down the right-field line like he can and hit a home run, and late in the game we'll have Marwin in for defense, and he's probably one of the best defensive infielders I've seen in a long time," DeFrancesco said.

Meanwhile, outfielder Fernando Martinez remains sidelined. He was scratched from Saturday's lineup with right knee inflammation and is hitting .360 in September, with a .485 on-base percentage and .520 slugging percentage.

"His knee is still cranky," DeFrancesco said. "He went to see the doctor the other day and there's swelling in there."