"I was able to put on my shoes today, so that was a bonus," Mauer said. "It's moving in the right direction."
Minnesota's training staff has put Mauer through a heavy regimen of stretching and warm compress since Sunday, but he still has not performed any baseball activity.
"If I come in tomorrow feeling good, I might be able to get out in the field and do some baseball stuff, which will be good," Mauer said. "It still hasn't changed. It's day to day. I'd like to get a bat in my hand ... before I get out there and compete."
Mauer had back pain prior to Sunday's series finale against the Orioles, but he hoped to play through it. In the third inning, though, Minnesota's All-Star first baseman knew something more serious was afoot.
"During the game when I came out, we tried to calm it down as best we could," Mauer said. "When I was swinging in BP, I noticed it was dragging a little bit. When I tried to get ready for the game, it came out pretty hard. I tried to stay out there and tried to get it loose, but the more I did, the more I aggravated it."
Chris Colabello has played first base in Mauer's absence, but made an error that led to a run on Tuesday.
Stephen Ellsesser is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.