Andy Murray surprised four excitable club tennis players celebrating their birthdays by asking them if they would like to have a hit with him.

The former world No 1 is currently in Philadelphia to work on his conditioning levels after ending his season early at the end of last month.

Murray has had a difficult season after undergoing hip surgery at the start of the year but has shown flashes of his old self during the few tournaments he has competed in since his return at Queen's in the summer.

But the 31-year-old was a picture of enthusiasm and warmth after being flagged down by four women playing at their local tennis club in America, and was more than happy to pose for pictures while the quartet couldn't quite believe their luck.

One of the women chartered their good fortune on their Instagram and highlighted how "kind, unpretentious and low-key," Murray was.