COACH Kamau Murray had a message for Sloane Stephens when she called him five months ago: “Let me know when you can walk.”

The 24-year-old was not allowed to put any weight on her left foot for 16 weeks after surgery following a stress fracture. She began hitting tennis balls sitting on a chair. Two months after her first tournament back, she won the women’s singles at the US Open on Saturday night.

Stephens lifted her first Grand Slam trophy on home soil – and a cheque for $3.7million (£2.8m) –with wide-eyed incredulity after her 6-3, 6-0 trouncing of fellow American Madison Keys in the final. Stephens plateaued after reaching her first major semi-final at the Australian Open in 2013 and turned to Murray ahead of the 2016 season.

The former college player combined coaching with a corporate job in pharmaceuticals until two years ago when he decidedto go full-time.

He also established a foundation in Chicago teaching tennis to underprivileged children and it was Stephens’ enthusiasm for that project that convinced him she was a player he wanted to work with.

There were positive signs prior to the injury that sidelined her last August, but neither could possibly have imagined how quickly major success would come. A key factor has been the sheer joy Stephens has found in simply being able to play tennis again.

“I think she has remained positive throughout the process,” Murray said. “You get the game taken away from you and then you come back, you start to appreciate it more.

“She legitimately loves to play tennis. She would call me, and she was all, ‘I can’t wait to get back on the court’. I was like, ‘Really? I’m enjoying my kids now, let me know when you can walk’.”

Stephens dealt with the inevitable nerves of a first grand slam final significantly better than Keys, her close friend and former junior rival, who was never able to settle into her game. “I was surprised,” said Murray. “That’s a nerve-wracking experience to walk out there. But I thought she handled it well.

Stephens had a taste of life at the top four years ago when she defeated Serena Williams to reach the last four in Melbourne. She has also had to cope with a lot in her young life, including the deaths of both her father and stepfather when she was a teenager.

“A lot of life has happened, a lot of good things and bad things have happened,” she said. “Every time you do something big it’s going to be different, so I’m sure now that I’ve won a Grand Slam things are going to be way different. I’m ready and prepared and I think my team and everyone around is excited.

“I’m going to try and keep everything like before. Obviously there are going to be more responsibilities and a lot of other things I have to do.

“There’s always going to be struggles. I’m sure there will be some ups and downs and some tough times. I’m actually looking forward to it. It will be challenging but super fun.”

Stephens’ victory capped a year of change on the WTA Tour, with the last three Grand Slam titles all won by players under 25.