Rod Stewart refused to give up playing soccer until it became "absolute misery".

Rod Stewart

Rod Stewart

The 70-year-old rocker ignored doctors' orders to give up his passion for over a decade, but had to quit the sport in 2013 after suffering a knee injury and still misses it "desperately".

He said: "I miss it desperately. For 13 years, I had doctors telling me I had to stop immediately. I did it until it became absolute misery."

And though he no longer plays full matches anymore, the 'Maggie May' hitmaker - who has eight children from various relationships - still can't resist a kickabout at home with his young sons Alistair, nine, and Aiden, four, who he has with wife Penny Lancaster.

Explaining a recently-completed workout involving a 30-minute bike ride and a lengthy swim, he added to Rolling Stone magazine: "I thought afterward, I'd just have a nice little sit in the sun.

"Then Alastair came down with his Celtic soccer ball and said, 'Come on, Dad. Let's go in the pitch!' I said, 'Oh, f**k, OK. Go and get me cleats, son. I'll be right there.' "

Rod never expected to have more children late in life, but is glad he did and is incredibly happy with 44-year-old Penny, who he married in 1999.

He said: "Having kids at my age was the last thing on my mind. But when you get married, women generally want babies. We're madly in love. Life is good."