Referee Phil Dowd reportedly employed a rigorous fitness routine over the summer to lose weight following criticism from former Manchester United boss Sir Alex Ferguson.
The Scot blasted the official when he struggled to keep up with the pace of play during the Premier League champions' 1-1 draw at Arsenal last season.
However, there have been reports of a slimmer, fitter Dowd overseeing fixtures during the pre-season, suggesting that he may have taken Ferguson's comments on board.
"He is like a different person. He looks fitter and more respectable for the weight loss. I definitely think people will be surprised by how much he's lost," the Daily Mail quoted Bolton Wanderers fan Callum Grundy as saying following a friendly between the Trotters and Real Betis.
"His performance was pretty good and he kept up with play without any issues. The topic of his weight loss came up numerous times in conversation between my dad, sister and mates during and after the match."
Dowd will be in action when the new Premier League season gets underway on August 17.