TORONTO -- Just when things looked to be on the upswing for the Toronto Maple Leafs, their blue line has taken another hit.

Toronto announced a few hours prior to Wednesday night's game against the New York Islanders that defenceman Roman Polak has been placed on the injured reserve list due to a viral infection, while Ron Hainsey was a late scratch due to illness after being a game-time decision.

Defenceman Morgan Rielly is already on the injured reserve with an upper-body injury and there is still no timetable for his return despite skating on his own on Tuesday.

It wasn't all bad news for Toronto on Wednesday, though. Earlier in the day, Toronto activated defenceman Nikita Zaitsev from injured reserve. He last played on Dec. 15 against the Detroit Red Wings, missing the past 17 games with a foot injury.

Without three of their regulars on the blue line, the Leafs recalled Justin Holl from the American Hockey League's Toronto Marlies on an emergency basis to make his NHL debut against New York.

The 26-year-old Holl, six-foot-three 205 pounds, has four goals and 20 points in 39 AHL games this season. He was originally selected 54th overall in the 2010 NHL Draft by the Chicago Blackhawks.

Holl, from Tonka Bay, Minn., was first brought into Toronto's organization in 2015-16 on an AHL deal before earning himself a two-way NHL contract at the beginning of 2016-17.

He recently played in the AHL all-star game as one of Toronto's two player representatives alongside forward Andreas Johnsson.

Leafs coach Mike Babcock went with Jake Gardiner, Connor Carrick, Travis Dermott, Andreas Borgman, Holl and Zaitsev against the Islanders.