"It seemed like it was 106," Mauer said Sunday. "He was throwing the ball at a good angle. It was the first time I've caught him, so it was good to see him. It's been pretty good to get to know these guys. Once we get out into a game, you start to get a better idea about the guys."
Gibson struck out two and gave up one hit in two innings, but the Minnesota Twins lost to the Tampa bay Rays 10-7 in 10 innings.
Facing longer odds of making the big league club, Rays reliever Juan Sandoval, attempting to pitch in the big leagues with one eye, struck out one and gave up one run and two hits in one inning.
"Sandoval was fine," Rays manager Joe Maddon said. "He threw the ball well."
Sandoval lost his right eye from an accidental gun shot while hunting in 2006.
"I look at it as a great challenge, but I'd look at it as a great challenge anyway," Sandoval said. "I don't even think about my eye anymore."
In his first spring training appearance, Mauer caught Gibson, a 2009 first-round draft pick out of the University of Missouri hoping to make the Twins' rotation coming off Tommy John elbow-reconstruction surgery.
He made nine appearances late last season after recovering from the Sept. 7, 2011, surgery. He showed promise two seasons ago, going 3-8 with a 4.81 ERA at Triple-A Rochester in 18 starts before the elbow gave out Aug. 2, 2011.
Twins manager Ron Gardenhire said he had fun watching Gibson on the mound.
"He's got a good angle. The ball comes out of his hand really nice," Gardenhire said. "We're not going to let him pitch any more this spring, just to be safe. Just kidding. He looks pretty good."
Mauer went 0 for 2 with a walk. He is scheduled to leave camp after this week to play catcher for Team USA in the World Baseball Classic.
Asked to compare Gibson to another pitcher, Mauer had trouble doing so.
"It's tough to compare somebody," Mauer said. "But he's got the height. He's got a good angle. He keeps the ball down."
Gibson said he worked on his slider, throwing three in the fourth inning and four in the fifth inning. He said he viewed his rehabilitation as over, although there were some things he would continue to do for the rest of his career.
"I think it's changed from rehab to prehab really," Gibson said. "I'm always trying to maintain. I think the program that I'm on is something I've been doing pretty much the whole time. I have to heat my arm up every day instead of just getting stretched. It's something that's become routine, and it's something I'll have to do every day for the rest of my career. It takes 45 minutes to get going. It's something I'm going to keep doing."
The Rays led 7-2 entering the ninth inning before a group of Twins minor leaguers rallied behind a three-run homer by infielder Brandon Boggs. The Twins scored five runs in the ninth.
Rays minor league catcher Michael Thomas hit a two-run homer in the 10th inning, sealing the victory.
Rays 3B Evan Longoria is slated to make his Grapefruit League debut Tuesday. Longoria left camp for four days for the birth of his daughter. Elle Leona Longoria was born Wednesday in Boca Raton. ... Twins 3B Trevor Plouffe, held out of action because of a sore right calf, is slated to return to the field Tuesday.