HOUSTON -- The Astros added depth to their pitching pool when they signed right-hander Clay Hensley to a Minor League contract and invited him to Major League Spring Training camp.

The two sides agreed to terms on Monday. If Hensley makes the team out of Spring Training, he'll earn $550,000. The contract also includes bonuses based on performance.

The 29-year-old Hensley, a native of Tomball, Texas, will compete for a starting spot but could also win a job in the bullpen. Over four seasons with the Padres from 2005-08, he has appeared in 106 games, 40 of which were starts.

"He'll come to camp and will compete as a starter and maybe as a bullpen guy," assistant general manager Ricky Bennett said in a phone interview with MLB.com. "We like his versatility. He's started and relieved in the past and had success in both roles."

Hensley, who attended Lamar University in Beaumont, Texas, was 1-2 with a 5.31 ERA over 32 appearances for the Padres in '08, including one start. In his career, he's 15-18 with a 4.09 ERA.

Hensley started last season on the disabled list with a right shoulder strain and was reinstated on June 6. He had shoulder surgery the previous September, which led to his DL stint to start the season. Hensley also made 16 appearances for Triple-A Portland, going 1-1 with a 3.94 ERA.

He reached a career high with 29 starts in 2006, compiling an 11-12 record and a 3.71 ERA. He made nine starts in 2007.

Hot Stove

The Astros have had their eye on Hensley for quite some time and tried to trade for him at the deadline a couple of years ago. Doug Brocail, who shared a bullpen with Hensley when the two were teammates in San Diego, also "highly endorsed" the right-hander, according to Bennett.

"When I talked to [Hensley's] agent, he said he was really excited about being an Astro," Bennett said.