Anthony Joshua was absent from the post-fight press conference following his defeat by Andy Ruiz Jr.
The deposed champion was undergoing a concussion test having been dropped four times before the world title fight was stopped in the seventh round.
Joshua put Ruiz down in the third round before taking two of his own visits to the canvas in the same session.
The Brit appeared to have recovered sufficiently but was dropped twice more in the seventh to seal his fate.
Joshua was being examined by the doctors as Ruiz reflected on his victory.
He joked: "I want to go and get in shape and look like the Mexican Anthony.
"Follow your dreams, if someone puts you down don't listen, just keep working like I did. We just made history.
"The way that I look. The extra flab I carry. I didn't want to lose much weight for this fight, I wanted to be strong as he's a big guy. Now I want to get in real good shape and look like a Mexican Anthony.
"I'm the first Mexican heavyweight champion of the world. I’m not going to let these belts go."
Joshua's promoter Eddie Hearn added: "I'd love to be able stand here and tell you that Joshua had a bad training camp, but I can't, because it wouldn't be true. He got beat fair and square by the better man.
"This will eat him up bad," added Hearn. "Some fighters lose and fight back, some never come back the same."
