Deontay Wilder was taken to hospital for examination following a stoppage defeat to Tyson Fury, several media outlets report.
Wilder suffered seven rounds of punishment in Las Vegas, Nevada as the "Gypsy King" produced a brutal masterclass to become world heavyweight champion again.
Fury's heavy beating left Wilder with an ear injury and his absence from the post-fight press conference led the Athletic reporter Mike Coppinger to tweet that it was because he was sent to "local hospital."
In his tweet, Coppinger said Wilder was taken to hospital for examination of an apparent ear injury along with general observation following a knockout defeat and seven rounds of punishment.
"It may have affected his equilibrium [in the fight]," said Wilder's trainer Jay Deas at the press conference. "He's going to get a couple stitches there."
The loss means Wilder's record falls to 42 wins (41 KOs) against 1 loss (1 KO) and 1 draw.
Speaking to ESPN after the defeat, Wilder said: Things like this happen. The best man won tonight.
"I was ready to go out on my shield. I had a lot of things going on, coming into this fight. My leg was already weak coming in, due to other little things.
"I make no excuses. I just wish that my corner would have let me go out on my shield."