Before sustaining a torn right groin on April 27 against the Padres, Patterson, 26, was one of the best starters on the Expos' pitching staff, posting a 3.57 ERA in four starts. After returning from the injury almost three months later, Patterson had a tough time pitching past the fifth inning and was often hit hard.

After coming off the disabled list, Patterson said he was constantly worried about reinjuring the groin and that played a role in his lack of success on the mound.

"The injury hurt me quite a bit," said Patterson, who was acquired from the Diamondbacks during Spring Training last year. "I couldn't push as hard. I had to baby things a little bit. That affected me. I didn't throw quite as hard. Mentally, I just never let it go. I just wanted to keep pitching instead of going back on the DL."

This season, Patterson expects to be the pitcher that he was before the groin injury. He said he is mentally tougher, and it was proven during his time in the Dominican Winter League. In five starts for the Licey Tigers, Patterson gave up just four runs on 30 innings. He also struck out 27 batters.

"I went down to the Dominican Republic and I pitched real well," Patterson said. "I pitched six or seven innings every start out there, threw 100 pitches and I kept striking out people. When I went to the Dominican, I stayed with the same game plan and it worked for me. It was just one of those mental things I had to get over. I feel confident I fixed that."

Patterson goes into Spring Training hoping that he could make the Nationals' rotation, but with the acquisition of Esteban Loaiza last week, Patterson, along with Jon Rauch and Michael Hinckley, currently find themselves in the bullpen.

"If you go into Spring Training and you do your job, then everything else takes take of itself," Patterson said. "If you don't take care of your business, that's when bad things are going to happen. I'm not concerned with it at all."

When asked if he would be better off in the bullpen considering that he dominated hitters in the early innings last year, Patterson said, "I did pitch a little bit out of the bullpen. I really don't want to comment too much on that because it hasn't crossed my mind. I'll cross that bridge when I get to it."