SIR ROD Stewart has teased he will get his "k**b done" after major ankle surgery that will see him grow an inch. 

The Celtic-daft crooner will be taller after the operation which helped to straighten the bones in his lower legs injured by years of playing football. 

In good humour, the 75-year-old - who is married to Penny Lancaster - joked he's going to get surgery done down below next.

Glasgow Times: Rod Stewart with his wife Penny Lancaster Rod Stewart with his wife Penny Lancaster

Speaking on Chris Evan's How to Wow podcast, Stewart said: “My knee got fixed with a knee replacement, so then the ankle didn’t know what was going on because obviously it’s crooked because of the knees, so now I’ve had to have the angle done. 

READ MORE: Sir Rod Stewart left in tears as 'Celtic family' perform special tribute

“So when this is done, I should have a straight leg and be able to run  — and then I’ll get my kn*b done.” 

When asked why by Virgin Radio’s Chris Evans, he said: “Mind your own business!”

Last month, we told of how the singer was left in tears by a tribute paid to him from Celtic fans across the world