Lupul did not practise Wednesday before the team was set to fly to Nashville to face the Predators. The winger was replaced on the second line by AHL call-up Josh Leivo.
Lupul, who missed the start of training camp with back spasms, played 18:38 in the Leafs' loss to the Colorado Avalanche. At one point he limped off the ice after an apparent knee-on-knee hit but did not leave the game.
Jay McClement, who missed the Colorado game for the birth of he and his wife's first child, was back on the ice at practice Wednesday.