De Haan, who was injured while breaking up a 2-on-1 in the final moments of the Islanders' 4-3 overtime win against the Los Angeles Kings last Saturday, has one goal and 11 assists in 33 games while averaging 18:44 of ice time. He's second on the Islanders with 65 blocked shots.
"Whether we're hopeful to get him back, it's kind of to be determined still," Weight said before the Islanders played the Winnipeg Jets at Barclays Center.
Weight said de Haan has not had surgery. He was placed on injured reserve last Monday.
Selected by the Islanders with the No. 12 pick in the 2009 NHL Draft, de Haan has 81 points (12 goals, 69 assists) in 304 NHL games. He can become an unrestricted free agent on July 1, 2018.
