Injuries continue to pile up for the Toronto Maple Leafs.

Phil Kessel left practice early with an unspecified injury, and coach Randy Carlyle said he wasn't sure if the star winger would be able to play Thursday night against the Dallas Stars.

The same uncertainty goes for centre Tyler Bozak and enforcer Colton Orr, who both missed Wednesday's practice. Bozak was getting an MRI on an upper-body injury suffered in Tuesday night's loss to the San Jose Sharks, while Orr was dealing with an elbow injury, according to Carlyle.

Kessel left practice in a hurry, telling Carlyle that he had enough. Carlyle relayed to reporters that the 26-year-old had a tweak in some part of his body but would not reveal any more.

Winger Joffrey Lupul, who has been out with a groin injury, skated before practice and then was on the ice with teammates for about 15 minutes before leaving in apparent discomfort.

Despite mounting injuries, the team put Jerred Smithson on waivers at noon ET. Carlyle explained the decision as having other players rated ahead of the veteran centre.

Defenceman Cody Franson, who missed the past two games with a lower-body injury, took part in practice and is hopeful he'll be able to return to the lineup against the Stars.

Centre Nazem Kadri returned to the team after missing Tuesday's game against the Sharks because of the death of his grandfather.