Lightning wing Ryan Callahan left Tuesday's game in the first period with an upper-body injury and did not return.
Callahan tangled with Leafs' Josh Leivo near the Lightning bench with four minutes left in the first. Callahan left for the dressing room appearing to hold his right shoulder. Both were given roughing penalties.
Coach Jon Cooper said Callahan probably won't join the Lightning on its upcoming two-game road trip to Brooklyn (Thursday) and New Jersey (Saturday).
"Hopefully it's not that long," Cooper said.
Callahan missed three weeks earlier this season after injuring his right shoulder in a mid-December game in Arizona.