Manager Brad Ausmus revealed the 30-year-old Zimmermann was hampered prior to and during Thursday's start -- his first outing after spending more than a month on the disabled list with a right neck strain.
The Tigers are preparing for Zimmermann not being able to start Tuesday against the Seattle Mariners.
"We're going to find out what's wrong with the lat before we make a decision on that," said Ausmus, who added that the problem isn't believed to be related to the neck injury.
"It would be a little bit of a gut punch (if he were to miss more time), but I don't think it would knock us to the mat."
Zimmermann was pulled after just 1 2/3 innings -- matching the shortest outing of his career. He looked uncomfortable from the start, giving up six runs on six hits -- including two home runs -- and his velocity was down and his location off.
The team hoped he'd loosen up as the game progressed, but Zimmermann instead was given the quick hook and replaced by Alex Wilson.
"He just couldn't seem to get loose," Ausmus said. "There was no pain. He just had trouble getting extended and locating the ball. So we went with him as long as we could but, ultimately, we chose to take him out."
Catcher Jarrod Saltalamacchia said Zimmermann was experiencing the same issue during his pre-game bullpen session.
Zimmermann gave up a run in the first after hitting leadoff batter Tim Anderson on the left hand. Anderson later left the game with a bruised hand, but X-rays came back negative.
The wheels came off in the second, however, when Zimmermann gave up a pair of home runs and left trailing 6-1. The Tigers' No. 2 starter now has a 6.44 ERA since May 1 after posting an MLB-best 0.55 ERA in the month of April.
"[You can tell] when a pitcher's not fully concentrated on executing his pitches, when he's trying to make himself feel good over anything," veteran second baseman Ian Kinsler said. "He's trying to work without discomfort and you can always tell when a player's doing that, whether he's on the mound or at the plate, and that always makes things more difficult."
Should Zimmermann require another stint on the disabled list, the Tigers could recall Daniel Norris, who was recently optioned to Triple-A Toledo. There is also the issue of the team possibly needing a fresh arm in the bullpen after Wilson, Kyle Ryan and Mark Lowe combined to pitch 7 1/3 scoreless innings.
With Mike Pelfrey going on the disabled list Tuesday with a lower back strain, the Tigers' current rotation is comprised of Justin Verlander, rookie Michael Fulmer, youngster Matt Boyd and veteran Anibal Sanchez.
The Tigers will wait to see if Zimmermann will remain a part of that group.
"Obviously we have to prepare for any contingency plans." Ausmus said.