Mike Tyson's trainer Freddie Roach has admitted that the former world champion could retire from boxing after his surprise defeat to Danny Williams.
The 38-year-old Tyson was knocked out in the fourth round by Williams, his fifth defeat as a professional.
"For Mike to walk away from boxing is definitely in my thoughts now," Roach told BBC Five Live.
"I'll talk to him and see how he feels. We'll make the right decision but it's not going to be based on money."
Roach added: "He doesn't have to fight for the money, there are other ways to make money.
"But it's so hard to retire from this sport. I was a fighter, I know.
"When I was told to retire I said 'no' and fought five more fights. I lost four of them."
Tyson made a promising start to the fight and appeared to have Williams in serious trouble with a succession of damaging body punches.
But Williams survived the onslaught and a rapidly-tiring Tyson had no answer to a string of Williams shots in the fourth.
"At the end of the second round Mike stopped moving his head and he was sitting right in front of Danny Williams," said Roach.
"The exchanges were great, it was exciting, but it wasn't good for Mike to take those kind of shots.
1990: First professional defeat, losing world heavyweight title to James 'Buster' Douglas in Tokyo
1996: After regaining the title, loses in 11th round to Evander Holyfield
1997: Disqualified for biting off part of Holyfield's ear in a re-match
2002: Challenges for world title again but loses to Lennox Lewis in Memphis
2004: Suffers fourth-round defeat to Danny Williams in Louisville
"He was giving and taking shots and that wasn't really the gameplan."
Roach was quick to give credit to Williams' ability to soak up Tyson's early attack.
"I didn't expect Danny Williams to take those kind of punches and still be standing. Mike hit him with some real hard shots.
"Mike told me he couldn't turn his left hook over hard because he hurt his knee a little bit.
"But there's no excuses. Danny Williams won the fight and I thought he had a great strategy.
"He wore Mike out and came through at the end.
"At the start I was excited and happy - I thought it was going to be over because Mike hurt Danny.
"Danny Williams was one punch away from being knocked out.
"But Mike couldn't get that one clean punch in and Danny survived. He showed a lot of heart."