Mauer took multiple foul balls off his mask Monday in a loss to the New York Mets and was scratched from the lineup Tuesday against Detroit when he began to feel dizzy during batting practice.
A Detroit doctor examined him and found some concussion-like symptoms. The same thing happened to fellow catcher Ryan Doumit during Minnesota's previous road trip.
"It was mainly he felt a little dizzy and out of sorts a little bit," Twins assistant general manager Rob Antony said of Mauer. "He did the baseline test, and they were pretty certain that he had the symptoms of a possible concussion. When you have that, that's why this rule is in place."
The All-Star catcher leads the Twins in batting average (.324), doubles (35) and OPS (.880). He spoke to reporters after Monday's game and didn't mention any concussion-like symptoms, nor did he appear to be in any kind of discomfort.
But while Mauer was shagging balls in the outfield prior to
Minnesota's 6-3 victory, a bit of nausea began to set in, enough that he immediately alerted the Twins' training staff.
He'll undergo standard concussion testing and have to wait until, at earliest, next Tuesday's home game against Kansas City to rejoin his teammates. He'll remain in Detroit on Wednesday, Antony said, but won't leave the team's hotel.
On Thursday, he'll go to the Tigers' Comerica Park and, pending medical recommendation, will fly back to Minnesota after the Twins' 12:08 p.m. contest.
"I think it's one of the best things (the league) instituted," Antony said of the seven-day disabled list, first used in 2011. "If you are shook up and you show some signs, it's best to be safe than sorry. You can put a guy on without saying, 'He was a little dizzy today, we're gonna put you out for two weeks when you might feel great two or three days from now.'"
To replace Mauer on the roster, the Twins called up first baseman/outfielder Chris Colabello from Triple-A Rochester. In 29 games with Minnesota, he's batting .221.
He was sent down when Doumit's stint on the concussion DL came to an end, but manager Ron Gardenhire said it was tough to see Colabello go.
Now, he'll have at least the rest of the Twins' six-game road swing to vindicate his major league manager's endorsement.