Garza, who was acquired in an offseason trade with the Twins, allowed two runs on four hits and a walk over 1 2/3 innings pitched.
"I was excited to pitch," Garza said. "Who doesn't get excited? First game out, new team, I was real excited ... to get out on that mound. [I'm] not happy with what I did, but happy with what I was able to accomplish."
Garza didn't make any excuses about his first outing coming against the Tigers, who have a potent offense.
"They're stacked," Garza said. "But what can you do? Keep making pitches, and keep getting them to swing at them. I threw a lot of strikes. They fouled off a lot of good pitches and they did what they did with the mistakes. .. The goal was to try and throw strikes, and I did that."
Last spring, Garza had to win a job with the Twins. This season he's already penciled in as the Rays' No. 3 starter, but Garza is not changing his approach.
"I'm still going out there competing," Garza said. "There's still a lot of talented guys in the locker room, you've got guys who want the job, just like I wanted it in Minnesota. It's hard to get on top. It's even harder to stay up there. That's the way I look at it, so I'm going out there competing every time out."
Rays manager Joe Maddon said Garza was on a 50-pitch limit, and had reached 47 when Maddon yanked him with two outs in the second.
"Stuff-wise he was fine, he just did not have the command he's looking for," Maddon said.
Tough beginnings: Highly-touted youngsters Jake McGee and Wade Davis have experienced tough beginnings this spring.
McGee, a left-hander, did not retire a batter Friday against the Reds, while right-hander Davis gave up four earned runs in an inning Sunday against the Pirates.
Maddon said those outings were forgotten.
"I'm not concerned," Maddon said. "They just have to get their first taste of this thing. They're very talented people. We'll get them both back out there.
"These are young guys that have very little experience; they haven't been around it before. The biggest thing now is not to let it impact their confidence in any way. It's early. It's different. I think they'll both be fine. They'll both throw a lot of strikes. I like their deliveries and arm action."
McGee fared better on Monday, when he got the final two outs in the fifth inning without allowing a run to score, but he still struggled with his control as he walked three in parts of two innings.
"He's not going out until about the sixth game [Wednesday]," Maddon said. "Just going on his past history, he doesn't need that many appearances. I think we figured maybe nine total. We'll try and get him in eight or nine times. But this is a normal routine for him. No specific reason other than it's normal. And so this is what he's comfortable with. I'm comfortable with it."
Maddon has familiarity with Percival from their days with the Angels.
"That's just how he's done it in the past," Maddon said. "With the Angels, many springs he made like seven appearances. That's the way he is. He's got this uncanny ability. Even if he hasn't pitched in a while, he's still able to throw strikes."
Kazmir update: Though Scott Kazmir has moved up to "Phase 2" on his recovery from a left elbow strain, Maddon said the left-hander is not yet to the point where he's throwing into a sock, which is a drill in which pitchers use a ball in a sock to simulate the throwing motion. Maddon did say he expects to see Kazmir throwing in the next couple of days. The Rays have not set a timetable for his return; Kazmir has said that he is determined to pitch the March 31 opener.
Up next: The Rays will host the Twins on Tuesday afternoon in a 1:05 contest at Progress Energy Park, home of Al Lang Field. Edwin Jackson will start for the Rays and will be followed by Andy Sonnanstine, Al Reyes, Trever Miller, Dan Wheeler, Gary Glover and Scott Dohmann. Boof Bonser will start for the Twins and will be followed by Dennys Reyes, Matt Guerrier, Brian Duensing, Carmen Cali, Kevin Mulvey and Ricky Barett.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.