The 29-year-old went down when he was hit near his right knee on a first-period clearing attempt against the Avalanche on Saturday.
"He's a big part of our team, a big body in our lineup," center Sean Couturier said after the game, according to Philly.com. "He's a guy we want to see in our lineup."
The Flyers signed van Riemsdyk this offseason to a five-year, $35 million contract after he had a 36-goal campaign for the Maple Leafs. He has one assist in two games for the Flyers so far.