The Islanders say Saturday that Tavares' status is day-to-day.
"I'm concerned, obviously," Islanders coach Jack Capuano said. "You know what Johnny is to our hockey club. He's not only a leader, but his play speaks for itself. He's not ready to go and we're not going to put him in a situation where he could further hurt himself."
The 23-year-old Tavares is tied for the club lead with 13 goals and is first with 39 points in 38 games. His consecutive games streak is the fifth longest in team history.
Tavares has missed only four games in his five-year Islanders career.