The team's leading point-getter is returning to Montreal to have his upper-body injury evaluated by team doctors.
The 29-year-old left-winger suffered the injury earlier in the week against the New York Islanders and was forced to leave the game in the first period.
Head coach Claude Julien provided a brief update on Tatar's status following the morning skate at Amalie Arena.
"Since the injury, it hasn't changed. He hasn't improved at all," said Julien. "They just want to send him there, get him to see our doctors, do some investigating into the injury and at least have some clarity."