Penny Lancaster and Rod Stewart. Picture: Bang Showbiz

Iconic rocker Sir Rod Stewart has promised to change his hairstyle if Celtic progress in the Champions League.

The 72-year-old rock legend is a life-long supporter of the Scottish soccer team and ahead of their opening game in Europe's premier club competition against Paris Saint-Germain tonight, Rod suggested he could alter his trademark spiky cut if the team progress to the next stage of the tournament.

He shared: "If we ever got to the last 16 of the Champions League ... well, I might just change my hairstyle."

Despite being born in London, the 'Maggie May' singer follows The Hoops on account of his dad Robert.

And Rod has also recalled meeting two of the club's most iconic figures, former managers Jock Stein and Kenny Dalglish, in the 70s.

He explained to Talksport: "A lot of people ask me, 'Why do you support a Scottish team when you were born in London?' Well, my dad was born in Edinburgh - he was a Hibernian supporter. And I met Jock Stein in 1974 with Kenny Dalglish and I sort of became a Celtic supporter then. It's because ... it's really indescribable, it's such a family, it runs so deep all around the world. I'm sure every supporter feels the same, but there's something about our team. It's just, just family ... that's the only way I can describe it, you know."

Rod - who recently renewed his wedding vows with his model wife Penny Lancaster - has been spotted shedding tears of joy on previous memorable European nights for Celtic.

And he's admitted to feeling emotional at the thought of seeing his team in action in the Champions League.

Looking forward to the big match, the chart-topping singer shared: "It sends a shiver down your spine, when the green brigade starts singing. Oh, I'm nearly in tears already and the game isn't even here."