John Hartson has admitted he is "surprised" UEFA will allow Atletico Madrid to wear a commemorative kit against Celtic.

The Celtic hero has been left baffled by the decision to allow the retro kit which marks the dirtiest-ever match between the clubs back in 1974. 

Atletico had three players sent off and seven booked in a goalless draw against Celtic in the European Cup before winning the second leg.

And the La Liga club will wear an exact replica of the kit worn in the notorious match when they face Celtic this week.

Brendan Rodgers rebuffed suggestions it could add an extra fire to the contest as he played down the significance of the kit.

He said: “Well, it will for you, probably. Clearly, you're looking for something.

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"The game was 1974 and I was what? One? I’m aware of the game and I obviously know that football has changed since that time as well. So no, my focus is purely on this game."

However, Hartson has claimed the kit could "incite" supporters during the Champions League group stage clash and questioned why UEFA hasn't ruled against the commemorative kit.

On Go Radio's Football Show, he said: “I’m surprised UEFA are allowing it to be honest. It could incite the fans.

"They [UEFA] get involved in every other blinking subject. Banning this and fining for that.

"Now you've got a team wearing a kit to commemorate the dirtiest game in football from 1974. I’m surprised they are allowing it."