The centre-back clashed heads with team-mate Kieran Richardson midway through the first half at Craven Cottage and the new boss is convinced that his side would not have lost 3-1 had he remained on the pitch.
|11/8||Fulham are 11/8 with William Hill to finish bottom of the Premier League|
"It was a big problem our captain was injured and wasn't there in the second half," the German told reporters.
"I don't know how Brede is. I hope he will come back and join us next week.
"I don't think we would have made such mistakes with Brede. He is the heart of the team and it was under control with him.
"He is a very important player for us. He is going to hospital so we have to wait. We hope he will be back next week to stabilise us."
Magath was also critical of Fulham's defending in the defeat on Saturday and vowed to put his players through more training drills to ensure that errors were not repeated.