Jos Luhukay says Sheffield Wednesday "must respect" the Football Association's decision to suspend Fernando Forestieri for three matches.
Forestieri will miss the Owls' up-and-coming Championship matches against Stoke City, Nottingham Forest and Aston Villa after admitting an FA misconduct charge following his involvement in the mass pre-season friendly brawl against Mansfield Town.
The frontman, who has scored two goals this season, was also fined £25,000.
Forestieri, captured from Watford in a £3m deal in August 2015, appeared to throw a punch at Stags midfielder Calum Butcher following the final whistle of the July 24 warm-up fixture.
He was also assaulted himself in the melee that followed, taking a blow to the head from another member of the Mansfield side as he tried to escape the bust-up.
Speaking on Forestieri's ban, boss Luhukay said: "It was a situation we did not expect. Three games is hard, first for Fernando and, of course, also for us.
"We now have three games where Fernando can't play for us but we must respect the decision from the federation.
"There's nothing we can do now. We have to accept it and must look after the Villa game where Fernando can come back into the team.
"He will train this week and also do some extra training next week. Every day he does very intensive work, not just in training but also individually and that is very positive. He is working hard to find a way back to the team."
The Star understands Forestieri is still being investigated on allegations he made racist comments towards Mansfield defender Krystian Pearce. The Owls "vehemently refuted" the claim.
The 28-year-old will next be available for selection against Leeds United on Friday, September 28.