McLemore has had problems with control this spring. He's issued a team-high 11 walks and has allowed seven runs over seven innings. His mediocre performance has allowed other rotation candidates to pull ahead of him.
"There are other people stepping ahead that could be of service in that role," manager Cecil Cooper said.
McLemore has been working diligently with pitching coach Dewey Robinson, who has encouraged the left-hander to stop thinking so much and just throw the ball.
"Basically, turn it loose," Robinson said. "Get mad and turn it loose. In my opinion, he's trying to be too fine. Just get it to a particular spot, and I think he's better off just rearing back and letting it go. Stop thinking about things and just go out there and throw like he knows he can."
McLemore is out of options on his contract, so if he doesn't make the 25-man roster out of Spring Training, the club will have to pass him through waivers before it can send him to the Minor Leagues.
In other words, this may be a last-chance scenario for McLemore this spring with the Astros.
"He needs to throw strikes," Cooper said. "I know that much. Options or no options, he has to make our club."
McLemore is the third starting candidate to be eliminated from the running. Fernando Nieve was sent to Minor League camp on Monday, and Felipe Paulino was recently shut down after being diagnosed with a pinched nerve in his upper right arm.
However, a new starting candidate has emerged -- right-hander Brian Moehler. The veteran entered camp this year as a non-roster invitee, a situation he's been in before. He wasn't one of the 11 starting candidates when Spring Training began, but as injuries and inconsistency become more of an issue with the staff this year, Cooper and his coaches will look at Moehler as a starting option.
General manager Ed Wade and Cooper plan to meet on Friday to discuss the matter.
"Brian's done a nice job down here," Wade said. "It doesn't hurt us in any fashion to [consider him for the rotation]. There's plenty of pitching opportunities left between now and the season to potentially let that happen."
Moehler was a starting candidate as a non-roster invitee last Spring Training but made the team as a reliever. This year, he was tabbed as a bullpen candidate but could break camp as a starter.
Cooper lauded Moehler's work ethic and versatility, and coupled with good spring numbers, that might be enough to win a spot on the team.
"Last year, he served just a gamut of roles for us," Cooper said. "He was the 12th guy, sometimes he was the 11th guy, he was the mop-up guy. He did a little bit of everything last year, really a trooper. He took to it and did it. He's a guy that can go a number of ways. He's a lot like [Chris] Sampson in a number of ways. He can start, he can pitch in the middle, a long kind of guy. Give him credit. He's come in here maybe with some odds stacked against him and he's pitched well."
Moehler is used to pressure and a little bit of turmoil this time of year, but the soft-spoken veteran makes sure not to let uncertainty affect his focus.
"What do I have to lose?" Moehler said. "Just go out there and pitch well. My whole thing is, I don't worry about what other guys are doing. I worry about what I'm doing. That's all I can control. I'm not a guy who picks up the paper to see what guys have done. I couldn't care less. I'm trying to make this team. That's my goal."
The nine pitchers either considered locks for the rotation or candidates for a spot are Roy Oswalt, Brandon Backe, Wandy Rodriguez, Woody Williams, Sampson, Shawn Chacon, Runelvys Hernandez, Jack Cassel and Moehler.