| Last updated
The 31-year-old hasn't fought since losing to Anthony Joshua back in December 2019 and he came under criticism for his physique.
Ruiz Jr has taken to Instagram to give fans an update on his progress and he is noticeably slimmer.
Andy Ruiz Jr Andy Ruiz Jr
In AJ Rematch Comeback Training
Dec 2019 Today, 2021 pic.twitter.com/6Gj21SxLpF
- Michael Benson (@MichaelBensonn) February 25, 2021
It was revealed last month that Ruiz has teamed up with Canelo Alvarez's trainer Eddy Reynoso to "get back on the right track."
He said: "I'm working hard preparing for whoever is next. Thank God we are on the right track.
"It's hard. I've never done this in my entire life. I never lifted weights. I never had a physical trainer like them. It's time to run. It's time to get it back. It's time to work hard."
The 36-year-old is known for his chiseled body but spoke fondly of the American in a chat with Gennady Golovkin.
Ronaldo said in DAZN's 'Parallel Worlds': "That's what I was talking about with my friends, because they made fun of him and told me to look at Ruiz's fat body," Ronaldo said.
"I would tell them, 'Listen, the body doesn't matter. What matters is preparation.'"
Since defeating Ruiz Jr, Joshua has gone on to defend his WBA, IBF, WBO, and IBO titles against Kubrat Pulev.
A huge clash with fellow Brit and WBC heavyweight champ Tyson Fury looks to be on the horizon, but Ruiz Jr thinks his former foe will fall short.
He told Little Giant Boxing: "I think that it's gonna be an interesting fight.
"I fought Anthony Joshua, I haven't fought Tyson Fury. Tyson Fury has a real style, he's tall, he fights tall.
"I kinda see Tyson Fury winning that fight. I wasn't too impressed with Anthony Joshua's last performance, but he got the job done.
"I think maybe Tyson Fury might get him, depends how awkward he is.
"If he boxes - Anthony hasn't fought anybody that boxes around and moves around, so we'll see."
Chosen for YouChosen for You
Most Read StoriesMost Read