KISSIMMEE, Fla. -- Players who received non-roster invitations to Spring Training are sort of like the understudies listed on a playbill: they're part of the group and they could eventually factor into the equation, but for now, they're not the ones garnering front-page headlines.

All 30 teams invite somewhere in the neighborhood of 15 extra players to camp every year, but with so few spots available on the Major League rosters, non-roster guys often come and go without any real chance to be with the club come Opening Day.

The Astros, however, could be the exception to the rule this year. They have jobs available and have invited a handful of players with good histories -- but also bad luck with injuries -- to big league camp.

If health issues don't get in the way, Houston's projected starting rotation could have a different look by the time camp breaks in six weeks. That's where a Russ Ortiz or a Clay Hensley or a Jose Capellan could force their way onto the team.

"We told them, 'Hey, look, there is a chance,'" manager Cecil Cooper said. "This is your opportunity."

The fifth starter job is earmarked for Brandon Backe, but in truth, competition is wide open. That alone could make the next few weeks in Astros camp very interesting, both for those competing for jobs, but also for those making the decisions in the front office.

Ortiz is a particularly interesting study. Now five years removed from his last full, effective big league season, Ortiz is attempting to continue a career derailed by injuries. He had two elbow procedures, including Tommy John elbow ligament replacement surgery, 18 months ago. He's worked tirelessly to come back, as he conveyed to several teams, including Houston, that attended one of his offseason workouts in Arizona.

The Astros liked what they saw and made an offer and a promise -- not for a big league job, but for a very real opportunity to win one. Other teams were more wishy-washy in that regard.

"They said, 'Yes, there is a real opportunity to make the rotation,'" Ortiz said. "The other teams were kind of like, they didn't know what opportunity was there. All I need to do is come in, show that I'm healthy and throw well enough. If I can do that, there is still a real opportunity here."

Hensley, a native of the Houston area, will also compete for a starting job, although a bullpen spot isn't out of the question, either.

Having grown up an Astros fan, Hensley's eyes were always on his hometown team, even as he navigated through parts of four seasons with the Padres. The Lamar University alum had shoulder surgery in September 2007 and subsequently missed much of '08, making just 32 appearances (one start) for the Padres.

Hensley said he was realistic about the opportunities he'd have this offseason and searched for a team simply willing to give him a real shot to make the club. That the Astros happen to be his hometown team was a bonus.

"We looked around at the pitching situation, not only in the big leagues, but also in Triple-A," Hensley said. "I grew up an Astros fan, always watched the Astros when I was a kid. I'd been telling my agent in the last three years, 'When we're a free agent, we're going to go to Houston.' When the opportunity came up, it looked like there were some holes, that they needed some pitchers and it seemed like a good opportunity."

Capellan will be in the starting mix this spring, but he has very little experience in that area at the big league level -- in fact, he's made only two starts -- five years ago. But he does have 64 games of Minor League starting experience.

The Astros generally like to keep their non-roster invite totals on the low side, realizing too many Spring Training participants usually equates to not enough playing time to go around. With 57 players in camp this year, everyone should be able to get a fair look. That includes a list of non-roster players that consists of young up-and-comers as well as veterans looking for a second chance.

"You don't want to turn anybody away that you think has a legitimate chance," general manager Ed Wade said. "So the numbers have to be somewhat fluid. One of the things you try to take into consideration is getting a legitimate chance to compete."

And that's all anyone appears to be asking for.

"My biggest thing is, I'm healthy now," Hensley said. "I feel like I'll be able to contribute when I'm healthy. I figured if I could just get in a situation where there was some opportunity to be on the big league club, the rest will take care of itself."