Former England lock Joe Launchbury will retire at the end of the season.
The 35-year-old was capped 70 times by his country between 2012 and 2022, winning three Six Nations titles and playing at the 2015 and 2019 Rugby World Cups.
Launchbury, formerly of Wasps, has made 50 appearances since joining Quins from Japanese club Toyota Verblitz in 2023 but has featured just six times so far this term.
"It has been coming for a while and it is certainly no secret, but the time feels right to step away from rugby at the end of this season," he told Harlequins' website.
"To have worn the England shirt 70 times, to have given so many years to Wasps, to have had the honour of representing Harlequins, and to experience a season in Japan. I've been so fortunate to represent the teams I have.
"To my team-mates, past and present, thank you. The friendships we have built go far beyond rugby. Not a day went by where I did not enjoy being around the people I was lucky enough to call teammates. You made every challenge worthwhile.
"Rugby has given me more than I ever dreamed of. Not just a career, but a life filled with purpose and friendships as well as memories that will stay with me forever.
"I have given my all to my career and my body is telling me it needs a break.
"I would love to stay involved in the game in some way, but for now I am looking forward to what comes next, and most of all, being present to watch my children grow up."
