In so many recent springs, Joe Mauer has been concerned with his back, or his knees, or the wear and tear awaiting him during the regular season, that he has eased through camp.Not this year. He's the top catcher on the USA team in the World Baseball Classic. He says he feels healthier than he has in years, and his at-bats are vintage Mauer.Tuesday night, he hit cleanup for the US and went 1-for-2 with an RBI double and three walks.Asked if he's ahead of schedule, Mauer said, ``Well, I just caught nine innings in mid-March, so I'm doing pretty good."Ever since TwinsFest, Mauer has seemed more relaxed and healthy than he has in years. At TwinsFest, I asked him when was the last time he felt this way. He couldn't remember.Now he's not placing any restrictions on his workload.``I felt pretty good tonight," he said. ``Last couple of days I'm feeling pretty good at the plate. I'm feeling good just getting into these games. There's a lot of excitement, It's a playoff-type atmosphere, and the body is feeling pretty good."Someone put a picture on Twitter of Mauer and Twins teammate Glen Perkins on a high-school All-Star team. Mauer looks remarkably similar now, while Perkins has grown a mountain-man beard.Is it safe to say Mauer has aged more gracefully? ``I have no comment on that," Mauer said with a smile.The US plays the Dominican Republic on Thursday night at Marlins Ballpark. Mauer will face fellow Twin Sam Deduno.Perkins did not pitch on Tuesday night.--------------------------I'll be back in Twins camp on Wednesday after spending a day at the WBC. I'll check in on 1500ESPN at noon every weekday. Please follow me on Twitter at @Souhanstrib.