"I make of it a guy having command of his fastball," Sveum said. "When you have command of your fastball down and away, in any kind of format in the big leagues, you're going to have success."
Welington Castillo had caught Garza's five previous starts, including May 31 against the Arizona Diamondbacks, when the right-hander gave up two runs over seven innings and picked up the win.
"[Castillo] has caught the other guys pretty well," Sveum said. "He's done a great job. However it works out, it works out. Welington Castillo has put himself in a situation where he's caught the [Scott] Feldman's and the [Travis] Wood's and the [Jeff] Samardzija's great outings. The things he's done for all these guys is well and above what a young catcher is supposed to do."
So, is Garza frustrated, or making excuses?
"You can call it what you want," Sveum said. "When you have fastball command, you can have [a Class A] catcher catching."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.