Deontay Wilder has been handed a six-week medical suspension following his defeat by Tyson Fury.
The American was dropped twice by his challenger last Saturday before the fight was stopped in the seventh round when his corner threw in the towel.
Wilder was suspected to have burst his eardrum and was set to be taken to hospital but he ultimately needed just seven stitches for a cut in his ear.
And the Nevada State Athletic Commission have now said Wilder cannot spar until April 8 and cannot fight in the state until April 23.
That will not prevent him triggering the rematch clause in his contract for third fight with Fury.
The loser of last weekend's bout had 30 days to do so and Wilder confirmed on Monday that he will seek his revenge.
"The rematch is definitely going to happen. We're going to get it on. I want to get right back to it," he said.
The trilogy fight was was due to take place on July 18 in Las Vegas but Fury's promoter Bob Arum has said it could be pushed back until September or October and be held at the new Las Vegas Raiders' stadium.
That could see a potential undisputed fight with Anthony Joshua delayed until 2021 after promoter Eddie Hearn said he wanted to make that fight this year.
Joshua is due to face mandatory challenger Kubrat Pulev at the Tottenham Hotspur Stadium on June 20.
Wilder, meanwhile, has blamed his 40lb ring walk costume for weakening his legs before losing to Fury.
He told Yahoo: "He didn’t hurt me at all, but the simple fact is that my uniform was way too heavy for me.
"I didn’t have no legs from the beginning of the fight. In the third round, my legs were just shot all the way through.
"But I’m a warrior and people know that I’m a warrior. It could easily be told that I didn’t have legs or anything.
"A lot of people were telling me, ‘It looked like something was wrong with you.’ Something was, but when you’re in the ring, you have to bluff a lot of things."
