Former Proteas fast bowler Morne Morkel will not return to Surrey for the 2021 season.
Morkel took 136 wickets during his three-season spell at Surrey, playing a key role in the 2018 County Championship success.
The 36-year-old featured in the Bob Willis Trophy during the summer, but suffered an ankle injury which required an operation after accidentally treading on a cricket ball before Surrey's game against Kent.
"Winning the County Championship in my first year at Surrey and soaking up the energy from our supporters and members – who are the heartbeat of the club – is something I will cherish for the rest of my life," Morkel said in an open letter on the Surrey official website.
"Unfortunately, the time has come to move onto a new chapter. The Covid-19 pandemic and subsequent quarantine requirements has made travel challenging and it is no longer feasible to spend large amounts of time away from home and my family.
"Surrey will forever be in my heart and I wish the team all the best for the coming season and beyond. I'll be watching and supporting from afar."
Surrey director of cricket Alec Stewart paid tribute to Morkel's contributions, but stressed the club would not rush to bring in a replacement.
"Morne has been outstanding for us in every way, delivering on the pitch from his very first game and playing a huge role within the dressing room," Stewart said.
"Whilst everyone will miss his presence and contributions, family must come first and with the uncertainty around the pandemic and travel restrictions, we fully understand and respect Morne's decision.
"Sourcing a suitable replacement for Morne will not be easy and therefore we won't make a decision on a new signing until there's more clarity on the international schedule and player availability during our season.
"We will only sign someone who we believe will add to the quality of our squad."
- TEAMTalk media