Danilo who joined Forest from Brazilian side Palmeiras in 2023, fell awkwardly after colliding with Bournemouth forward Antoine Semenyo. The match was delayed for several minutes as he received medical treatment on the pitch.
Forest went on to draw the match 1-1 with Bournemouth.
"It's a tough moment for all, especially for Danilo. We don't know yet what has happened but we know it's serious," Nuno told Sky Sports.
"We're going to miss him as a player and a person. He is a top, top (person)."
Danilo has scored six times and provided four assists in 49 appearances for Forest.
"Since last season he has been talented in the way he manages the game. He is a very good player so it is a tough moment. Everyone loves him in the dressing room," Nuno added.
Forest next visit promoted Southampton in the Premier League on August 24th.
