Gallen scored a third-round stoppage over Darcy Lussick on Wednesday in Sydney to take his record in the ring to 11-1-1.

Cronulla's only premiership-winning captain had to withstand an early barrage from Lussick but his endurance and toughness helped him survive to leave his opponent punch-drunk and dazed.

Gallen has stated that 2022 will be his last year in the fight game and, while a bout with Williams has been speculated about for the best part of a decade, the 40-year-old doubts it will ever come to fruition.

"I don't think that fight will ever happen," Gallen told AAP.

"He said he wants 10 fights in the next two years and I dare say I'll be at the back of the queue.

"I won't be fighting beyond next year. My wife and kids don't want me to. I've been a professional athlete for the last 20 years and I want to start enjoying my life.

"I have two fights left on my deal, but I have no idea who that will be. We'll have to see what (promoter) Matt (Rose) comes up with."

Gallen appeared to struggle early against the rangier Lussick, but after composing himself his experience began to tell.

Lussick was clinging onto Gallen at the end of the second round before falling to the canvas and surviving just 20 seconds into the third.

Gallen said the chance to scoop $20,000 for the best knockout of the evening, the winnings for which he opted to split to victorious Australians Harry Garside and Sam Goodman on the night, blurred his tactics in the opening round.

"I had to be smart and to be honest, I wasn't," he said.

"When there's $20,000 up for grabs and just three rounds, you've got to throw bombs.

"It wasn't until the second round I tidied myself up and parried him away and dropped him at the end of the round."

Australian Associated Press