Astros agree to $2.9 million deal with Carlos Pena

Pena started his career with the Rangers, and has hit 277 homers with 791 RBIs in a 12-year career that also had stops in Oakland, Detroit, Boston and with the Cubs. He has history with new Houston manager Bo Porter, having played with Porter in spring training when he was in the Rangers minor league system.

He's undaunted by the fact that Houston has lost more than 100 games in each of the past two seasons and isn't expected to contend in its move to the powerful AL West next season.

Pena was in a similar situation in Tampa Bay. They Rays had lost 95 and 101 games respectively in the two seasons before he joined the team. They lost 96 in his first season there in 2007 before winning 97 games the next season and reaching the World Series.

"It actually was inviting to me," he said of joining a rebuilding team. "I've been on teams where we were thought to be the worst in baseball at one point and very quickly, sooner than anyone expected, we were in a World Series. So I've seen things change very quickly. ... I like the challenge that it presents and the potential for growth."

Some had speculated that the signing of Pena would eliminate the possibility of the Astros bringing back slugger Lance Berkman. Luhnow said that wasn't the case.

"We need to do everything we can to improve this team," Luhnow said. "And if we get to a point where Lance is interested in playing and we find that we can utilize him, which we obviously can if he's healthy, then we'll have a conversation with him."