Shirley made her announcement "with a heavy heart" at the Squash Southland awards, calling time on a career notable for a long list of highlights including being named Southland Female Player of the Year five times and winning the national B grade teams event as part of a combined Invercargill club team in 1999.
She has also been a Southland C grade (once) and B grade (13 times) champion, Squash City women's club champion six times, Southland 45-54 age group champion nine times, a two-time Southland Open champion and six-time Southland Masters Women's champion.
One of her proudest achievements was to make it to A grade level, albeit for two weeks.
"I've been extremely lucky to have been able to do what I've done."
Shirley grew up at the Blues squash courts which her parents helped to establish on Conon St, making an early impression with a couple of South Island under-13 girls' titles.
Ironically, it was the amalgamation of the Blues, Old Boys and Invercargill clubs which prompted her first retirement, coinciding with a career highlight as a combined Invercargill club team won that national B grade teams event.
"At the time those clubs had just amalgamated and I'd decided to hang up my racket because my heart was with my old Blues club. We had been trying for that title for so many years and I felt like I'd achieved all I wanted to in squash, but apparently that wasn't the case because I came back again."
Thirteen years later, Shirley found herself venturing through the doors at Squash City in what would become the second act of her squash career.
"I went down to watch my niece and the atmosphere was so cool with this new club and I had got over my wee tantrum about the clubs amalgamating."
It wasn't all straight forward. In her first or second game back playing against Pauline Fairweather, Shirley snapped her Achilles tendon and was out for the best part of a year.
When she returned, she won the club championships and she hasn't looked back. Inspired by the longevity of Jan McAra, Shirley has worked hard to maintain her game and has loved being part of Masters events for the past decade, since going away with a Shaun Madden-coached Southland team for the first time.
"It's the people, the atmosphere. It's like a family with people who have the same passion as you.
"I'm going to miss that dearly."
Being such a competitive spirit, Shirley said she needed a clean break from the sport and was looking forward to doing some more caravan trips.
"It's going to be tough. I know if I go down to the courts I'm going to want to get back out there. Like I said in my speech, it's with a heavy heart because I'd love to keep doing what I do, but I can't. I don't want to go backwards. The mind still wants to do what the body can't," she said.
Shirley will retain at least one link with the sport, after donating a trophy titled the Debs Shirley Masters Squash Personality of the Year, to be presented annually at the Squash Southland awards.
The inaugural winner of the award was Andrea Dudley, a team-mate in the Southland Masters team. - APL