Ronald de Boer was left stunned at the ferocity of tackles flying in during the Old Firm and the lack of intervention by the referee. One of the biggest derbies on the football calendar returns this weekend as Rangers host Celtic in the Premier Sports Cup.
De Boer's Old Firm experience
The two Glasgow sides meet at least three times in the league each season, with one more clash possible after the split, with potentially two further domestic cup clashes if results and draws pit them against each other. De Boer played in this fierce contest on 12 occasions, registering five wins, five losses and two draws.
Speaking to BBC Scotland in 2017, the former Rangers star admitted he was taken aback at just how many potential fouls were ignored by match officials during the game. De Boer said: "The experience was like, you've heard about it and people say you've never experienced something like this before and it was true. It was amazing.
"Red eyes, like angry wolves"
"And you see the change in the Scottish players, a button turns: red eyes, they're like angry wolves. They were in another world and they kicked everything that was green and white, vice versa also. I'd never seen so much kicking in my life in a football game.
"And the referee was like, 'it's okay'. Normally in Holland, it would be a red card or at least yellow. The intensity - an unbelievable privilege to stand on the pitch. It's part of life as a Glaswegian."
Comparison with El Clasico
The Champions League winner joined the Gers from Barcelona in 2000 after winning the league title in Spain. He went on to put the Old Firm at the same level of passion as El Clasico, claiming even his former La Liga teammates were in agreement.
De Boer added: "I always say: El Clasico, not far in comparison with intensity with Rangers v Celtic. You feel it, even the Barcelona players say that, when they go to Celtic Park, when they lost when Rod Stewart was crying, it was a great moment."
Passion of Scottish fans
"The intensity - an unbelievable privilege to stand on the pitch. Everywhere I go, if I go to Dubai or Australia, and you meet Scottish people, in Holland maybe they'd never say 'I'm a Feyenoord fan' or 'I'm an Ajax fan' - [the Scottish people say] 'I'm a Celtic fan' or 'by the way, I'm a bluenose' always - until they die.
"It's unbelievable, it's so in their veins and in their blood. It's part of life as a Glaswegian."
During his time at Rangers, the attacker won the league title, two Scottish Cups, and the League Cup as he helped the club threaten Martin O'Neill's dominance at Celtic. Now the Northern Irishman is back in the hot seat in Glasgow, 20 years on from his initial stint as Hoops manager.
The 74-year-old will lead his side into Ibrox with zero away fans in the ground following a ban on supporters due to the chaos caused during last season's Scottish Cup quarter-final. De Boer will likely watch on with hope that Rangers can create some unrest in Celtic's recent silverware-laden years.
