JUPITER, Fla. -- Kyle McClellan is thinking, and that's never a healthy thing for a pitcher.

Thinking about how to sort out his mechanics. Thinking about how each part of his delivery needs to fit. All instead of thinking about the one thing he needs to have on his mind: executing good pitches in the strike zone.

It's led to a frustrating and mostly ineffective spring for the right-hander who pitched his way onto the Cardinals' Major League roster last spring. McClellan has a 10.64 ERA in five Grapefruit League appearances. He's allowed 17 hits in 11 innings and has as many walks as strikeouts (five). It came to a head on Saturday against the Nationals, when McClellan was charged with six runs on six hits and two walks in one inning.

That showing allowed the Nationals to turn a blowout into a close game. Once ahead, 12-2, the Cardinals won, 12-11.

"My mental approach is what got me in trouble yesterday," McClellan said Sunday. "It might have been [because it was] a 12-2 game. It might have been thinking about my mechanics instead of what I'm doing at home plate. There's a lot there. It's an all-around bad outing. I lost sleep last night. It's embarrassing. I feel like I embarrassed myself. It's a pretty [bad] feeling to walk in here today and everybody look at you and know what happened yesterday."

What made it especially frustrating was that one game earlier, it appeared McClellan was starting to get sorted out. He pitched 1 2/3 effective innings against the Orioles on Wednesday, the first time since games began that he felt he was really getting somewhere. Then, on Saturday, the bottom fell out again.

Manager Tony La Russa took issue with McClellan's state of mind in the Saturday game, singling him out in his postgame news conference.

"Hopefully Kyle learned a valuable lesson," La Russa said. "I think he came out there and just wasn't concerned enough that anything bad could happen. He was out there just aiming it to the plate. He didn't throw a lot of strikes, didn't throw a lot of quality strikes. So it's a lesson. Fortunately, we didn't lose."

The frustrations have raised a disquieting thought in McClellan's head. After beginning the spring as an apparent lock to make the Major League roster, he admits it's crossed his mind that nothing is assured even after an outstanding rookie year.

"There's no guarantees at all," McClellan said. "There's no reason for me to think that the way I pitched yesterday is going to make me have a job here. We've got the best pitching coaches with [Dave] Duncan and [bullpen coach Marty Mason], so I'm going to work with them. We talked about it today. I need to get back to where I was last year, attacking the zone and concentrating on making pitches. I think yesterday, by the time I went to do that, I was thinking about so much mechanically, thinking, 'Do this, do that,' and not at all thinking about [making pitches]."

McClellan has Minor League options remaining, and the Cardinals have a bullpen crunch. They have six right-handed relievers for five jobs. But while La Russa and Duncan acknowledge McClellan is in something of a competitive situation, both cautioned against overstating things.

"I expect he'll be right in two weeks -- sooner than that," La Russa said.

Duncan will have McClellan throw a bullpen session Monday rather than pitching in a game. Then, McClellan will be back in action Wednesday. The hope is the side work will allow McClellan to smooth out his delivery so he can get back to concentrating on the important things.

"I think it's realistic," Duncan said when asked if McClellan must compete for a roster spot. "I think there are several guys that are in a competitive situation. But I wouldn't make a big deal out of it. He's going to get the benefit of the doubt."