"Losing ... I'll never get used to that," Minnesota manager Ron Gardenhire said after the Twins dropped to 4-9. "Plain and simple, I don't care what time of the year it is."
Mauer was placed on the 15-day disabled list Thursday because of leg weakness stemming from offseason arthroscopic surgery on his left knee. Tests on Mauer, who was taken to a hospital Thursday night with flu-like symptoms, found he has a viral infection, which the team believes increased the catcher's body soreness recently.
"It tells us that there's probably a reason why he's been so sore, and that's his system is fighting a viral infection," Gardenhire said. "It kind of helps us in probably knowing a little bit better where we stand and what's really going on."
Gardenhire hopes Mauer will be able to return in a couple weeks.
"I think it eases everybody's mind knowing he's got a viral infection, flu-bug thing, and we all know how you feel when you get that stuff," Gardenhire said. "Probably got him feeling worse than he probably really is."
Davis (1-2) limited the defending AL Central champions to three singles and Danny Valencia's fifth-inning RBI double to help the Rays to their fourth straight win and fifth in seven games following an 0-6 start. Minnesota has dropped three in a row and five of its last six.
"As I told the boys in there, this game doesn't give you anything," Gardenhire said. "You have to take it. We need to start taking a little more than we're givin'."
A night after beating the Twins with a 10th inning homer, the 37-year-old Damon delivered a two-run single off Nick Blackburn (1-2) to erase a 1-0 deficit in the sixth. Shoppach finished off the Minnesota starter with a two-run, seventh-inning homer for his first RBIs of the season.
"I just started leaving some pitches up," Blackburn said. "I didn't quite execute as well as I did the first five innings."
Sam Fuld and Matt Joyce each had three hits for Tampa Bay, which has scored 37 runs in its five victories compared to 12 in its eight losses. Damon has hit safely in seven consecutive games after going 1-for-15 while the Rays were losing five straight home games to begin the season.
Damon's two-run single put the Rays ahead and Upton's RBI double later in the sixth hiked the lead to 3-1 against Blackburn, who narrowly escaped being hit by a line drive hit by Joyce during the inning. The ball deflected off the pitcher's glove and rolled to shortstop for an infield single.
Shoppach put it out of reach with a first-pitch, two-run homer off Blackburn, who allowed five runs and 10 hits in six-plus innings.
Notes: Minnesota DH Jim Thome entered the game 2-for-2 with two homers lifetime against Davis. The slugger hit a fly ball to the warning track in center field in his first at-bat and finished 0 for 2 with a walk against the Rays' starter. He scored the Twins' first run when he drew the walk before Valencia's RBI double. ... Shoppach has three homers in 15 career at bats against Blackburn. ... Blackburn is 2-3 with a 6.66 ERA in five starts against Tampa Bay.