The Cubs' right-handed reliever had given up one run in his first five appearances but has not been able to get anyone out in his last two games. He's given up four runs on five hits and one walk in the last two appearances.
"It's bound to happen sooner or later," Wuertz said. "Now is not the best time, but it's only two times. You get over it and move on."
On Sunday against Philadelphia, Wuertz entered the game in relief in the sixth and served up a home run to Eric Bruntlett, then gave up three straight singles before he was pulled.
On Tuesday against Cincinnati, the right-hander came into the game in the ninth and served up a leadoff homer to Joey Votto, then walked Paul Bako before Cubs manager Lou Piniella made a switch. Both homers -- Bruntlett's and Votto's -- came on the first pitch.
Wuertz had a good spring, so the latest glitches are a little surprising.
"I still feel good," he said. "It's a matter of staying aggressive and getting back on that track again and forget about what happened. You come in here and flip the page. It's not the end of the world. You just go out there and have fun.
"It's just a matter of executing pitches and being aggressive and not giving in too much. I just have to do the things I'm capable of doing, not anything more or anything less."
Wuertz's best pitch is his slider, and he needs to do a little tweaking.
"I need to be a little bit crisper with it," he said. "I've been throwing a little too hard velocity-wise. I don't know if it's because I feel good. I just have to back off a little and make pitches. You have to be aggressive and know when to back down. Just stay relaxed, I guess."
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.