Fulham midfielder Lucas Piazon has a suspected broken leg, according to Slavisa Jokanovic.
The 23-year-old was on the end of a heavy tackle shortly before half-time and was helped off the pitch by Fulham's medical side.
Jokanovic confirmed it is a bad injury and was livid with comments he had heard regarding the tackle, claiming they were some of the worst things he has heard in professional football.
He admitted he had not really seen the challenge, but was more infuriated by the comments.
"It's very bad injury. We have lost him for long time. I believe it's a broken fibula," Jokanovic said.
"It's not a question about complaining; it can be bad luck, it can be a tackle outside of the norm.
"But I am really disappointed with what I heard today, one of the referees saying: 'this is English football, this is completely legal'. I am 48 year-old man and I've never heard an ugly answer like I hear today."
Jokanovic was asked to clarify his comments further, but would not be drawn into explaining them.
"It's not important," he went on to add. "We don't need to go so deep into it. I am personally a little bit disappointed.
"I hear something, it's probably because my English is not great, because it's so ugly and I never expected to hear it in professional football.
"I'm disappointed in comments from people who need to care and save the players. I was simply surprised to hear that.
"I've never heard such silly commentary about a complex situation like I heard today."
