Danilo, a Nottingham Forest midfielder, is expected to have surgery for a broken ankle.
The 23-year-old is a crucial player for the City Ground team, but he may miss the most of current season.
Manager Nuno Espirito Santo acknowledges the club is just hoping that the procedure goes well and that he recovers properly.
“We miss him. It was dreadful. It was a huge loss for us to not have him. “Now it’s just about wishing him the best,” the Portuguese remarked of Danilo this week.
“According to our recent information, it is a major injury. But we’re optimistic he’ll be back strong and ready to play.
“We miss him so terribly. Everyone adores him.
“It is always heartbreaking when you lose a player, no matter who it is. They are always concerned about their health and work hard to ensure that everything is in order before competing.
“When you lose someone, it’s incredibly upsetting, especially when you know he’ll be gone for a while. But that is football, and as a squad, we must be prepared for anything.”