The Metro reports that the 42-year-old supporter, who wished to remain anonymous, worked as a builder on the site as Liverpool renovated the Main Stand this summer.

But while working on the project, he left a naughty surprise on the roof.

The construction worker decided it would be funny to leave a United shirt on the roof and stick a pair of figurines to one of the steel supports within the stand.

The United fan, who lives in Lancashire, attached miniature versions of Ryan Giggs and Rio Ferdinand to the stand with a special adhesive, ensuring they had one of the best views in the house for the bitter clash on Monday night.

He said of the prank: “I was working with a load of Scousers and I thought this would be a good way to wind them up.

“It’s all just a bit of good-natured banter. There’s a lot of nasty things that get said between the two sets of supporters, but I’m not about that.

“The lads I worked with were great, but every time they tested the public address system, I had to listen to You’ll Never Walk Alone.

“I thought I’d leave my own mark on the stadium and remind them who was the best.

“There were quite strict rules about football colours being worn by people working on the stadium, but one day I wore mine under my hi-vis and sneaked it up.

“I had little Giggsy and Rio collectables from a few years ago and they both scored at Anfield in the past so I thought it would be nice to give them a good view of the pitch.”

The father-of-four had been working at the stadium for six months but saved his cheeky prank just before the unveiling of the new stand.

And he explained exactly how he got away with it.

“I basically had to reach the bits that the scaffolding couldn’t get to, working on cladding and pipes and things,” he added.

“Obviously I had to be a bit careful not to get caught but it’s all just a bit of fun. I was working on the gable end nearest to the Kop so the thought of the shirt and the two figures overlooking it makes me smile.

“I was born in 1974, the first year United were ever relegated, and where I went to school I was one of only two United fans.

“So this is a little bit of payback I suppose for getting the mick taken out of me when I was younger and United weren’t very good. It’s just a bit of craic.”