Van Riemsdyk is dealing with back spasms that are likely to cause the forward to miss his second straight game Thursday when the Carolina Hurricanes visit Air Canada Centre in Toronto. He's considered day-to-day but there's no specific recovery time.
"He did skate (Wednesday), and we felt that was an improvement," Carlyle said. "But he's kind of plateaued or flattened out here, and we're not going to put him on the ice in a situation where we think we're going to possibly have him have any setback."
Carlyle had previously said he was "surprised" that the injury occurred and called it upper-body. He said van Riemsdyk did not suffer the injury in a game.
"He got up the other morning, got to the rink, he had back spasms," Carlyle said. "That's why it wasn't a hockey-related injury. We all know that skaters get skaters back. It's one of the things that hockey players have to deal with over the course of the season."
Van Riemsdyk has five goals and an assist in his first six games of the season. He took Monday off as a so-called maintenance day and did not play Tuesday against the Minnesota Wild. The 24-year-old left Wednesday's practice early because he was "pretty stiff," according to Carlyle.
Carlyle does not believe van Riemsdyk has a history of this kind of problem.
"I just think this is one-off for him, specifically," he said. "Because he has back spasms one day, is that a history? I don't know that. I don't think we can predict that yet. It's not something that's been noted in his medical file. But I would guarantee you there isn't a player in there that hasn't come to the rink with a bad back."
Dealing with players being out of the lineup is nothing new for the Leafs. They're already without wingers Nikolai Kulemin (bone chip in right ankle) and David Clarkson (10-game suspension), enforcer Frazer McLaren (broken right pinky finger) and defenceman Mark Fraser (knee).
That has meant calling up players like Josh Leivo, Trevor Smith and David Broll from the AHL's Marlies and plugging them into the lineup. Van Riemsdyk's injury earlier this week just opened up another spot.
"With us, we've been constantly having to make adjustments to our roster based upon the availability," Carlyle said. "We've been dealt a few of those situations that we call adversity, but that's to be expected early in the season and every team in the league has their fair share of injuries.
"For us, we have some young kids now that are stepping into the lineup who are getting an opportunity to show us what they have, and they're trying to earn the trust of the coaching staff."