Famously nicknamed 'Il Pitbull' for his tenacious displays from defensive midfield, the hirsute AC Milan legend has undergone a shock transformation.
Currently managing iconic Croatian side Hajduk Split, the club posted a video online of their coach having his beard shaved off for charity.
Rather incredibly, the 46-year-old revealed it's the first time he's been clean shaven in 22 years, back to the start of his playing days.
More shocking than that, though, was how different he looked, with a second glance needed to recognise one of Italian football's most famous faces.
Underneath the beard there was understandably a big smile, as the feat raised a whopping €10,000 [£8200] for charity.
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Players, staff and fans joined in, with a total fee of €150,000 raised for 250 beards and moustaches to be trimmed away.
The 'Beard Auction charity campaign' is a humanitarian project dedicated to promoting men's health, supporting the anti-cancer leagues in Split, Vinkovci and Pula.
The act will further endear Gattuso to supporters, given that two games ago his side won the country's biggest match against Dinamo Zagreb 1-0 to go three points clear at the top of the league, a lead they lost next time out.
However, Gattuso continues to show his talent as an underrated coach, having previously come in and stabilised difficult to manage clubs in Milan, Napoli, Valencia and Marseille, even winning the Coppa Italia with Napoli.
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Gattuso retired from playing in 2013 and his ambitions in coaching were soon clear, as he would reveal that he once spent three days in a car waiting to meet Pep Guardiola.
"When I was 27 or 28 we faced Barça with Xavi, Iniesta, Ronaldinho, Messi… And something happened inside me," he told L'Equipe while coaching Marseille.
"We ran for 95 minutes, I did a marathon in each game against them and touched the ball three or four times. We didn't understand what was happening. So I started to get interested in the issue, I studied, I analysed…
"I spent almost three days outside Bayern's training ground, waiting to see Guardiola's car arrive. I hadn't asked anyone for anything because I don't like asking for favours.
"He recognised me when he passed us, but we had already been there the previous two days. Gigi [his assistant] and I were freezing to death."
As a player, Gattuso won the World Cup in 2006 with Italy and picked up two Champions League titles with Milan, plus two further Serie A crowns.
Regularly paired up with countryman Andrea Pirlo in midfield, the duo created one of football's all-time great partnerships, and both stood out due to their iconic hair and beards.
Gattuso also represented Italian side Perugia as well as Scottish giants Rangers and Swiss outfit Sion during his 18-year playing career.
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