So how did the Padres decide between Garces -- who made the team's Opening Day roster -- and fellow rookie southpaw, Chris Rearick?
"Right now, the consistency of the breaking ball with Chris is a little above Frankie," manager Bud Black said before Saturday's game. "And there's some things that I think Frankie can benefit from in the Minors."
Garces had a 1.59 ERA in six games and 5 2/3 innings. He allowed three hits in nine at-bats against left-handed batters with one walk. Rearick, added to the roster from El Paso on April 10, has allowed two earned runs over 2 1/3 innings. He's allowed two hits in four at-bats to lefties, including a home run.
But Black and the organization feel that Rearick's ability to spin a slider against a left-handed better, with some deception in his delivery, is a weapon.
"We like some of the things he does with his slider against the lefty that might help us here through this period, early part of the season," Black said.
Black said not to be surprised if Garces is back in the big leagues at some point.
"These are two young pitchers who are still finding their way," Black said. " ... This spring, I thought they both threw the ball well. As we go through this, I think both guys will end up helping us win games."
Rearick put himself firmly on the team's radar with strong performances during Spring Training, as he didn't allow a run in 10 of his 11 appearances.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.