"I'll be ready when the bell rings," said Garza, who allowed 10 runs, six earned, and nine hits in a Los Angeles Angels' split-squad's 12-2 win over the Brewers.
Los Angeles starter Hector Santiago continued his solid spring. He allowed five hits and two earned runs in 4 1/3 innings with six strikeouts in his third spring outing.
The Brewers committed two errors in an eight-run Angels' second.
Garza reportedly rejected more money from the Angels to sign a four-year, $50 million contract with Milwaukee.
"They put the ball on the ground and what happened, happened," Garza said. "That's the way it broke down. Thank God, it's spring training."
Garza signed a four-year, $50 million contract with the Brewers after going a combined 10-6 with a 3.82 ERA over 24 games with the Chicago Cubs and Texas in 2013.
"He's not spotting balls as he usually does," Milwaukee manager Ron Roenicke said. "He had no rhythm. And, of course, we didn't help him out."
Garza said he had to grind it out.
"I could only say 'keep pitching,' " Garza said. "It's more about me showing the guys what I can do."
Roenicke would like to see that soon.
"I would like the next one to be better," said Roenicke, who when asked, said he's keep putting Garza into 'A' games to get him straightened out. "He's got three more starts. I'm not concerned about (only) three starts."
Santiago had to get loosened up again as he went out for the third inning after the big Angels' inning. He told reporters that he pitched against a net in the tunnel.
Santiago is in competition for one of two open spots in the back end of the Angels' rotation with Joe Blanton, who fired five shutout innings in a split-squad Angels' win Wednesday.
The Brewers' defense left a lot to be desired in an eight-run Angels' second and Garza deserved a much better fate.
First, Rickie Weeks was unable to come up with Hank Conger's hard double play ball at second for an error. Matt Long followed with a bouncer up the middle that went under shortstop Jean Segura's glove for a hit. Kole Calhoun then scored from first on Mike Trout's ground single to left as third base coach Keith Johnson aggressively waved Calhoun around third as the throw came into second and Weeks' throw home was late.
Later, Segura was unable to handle a relay throw that allowed Albert Pujols to slide in safely at third.