South Africa fast bowler Morne Morkel has left Surrey following three years at the Kia Oval.
The 36-year-old helped the club win the County Championship title in 2018, taking 59 wickets at an average of just 14.32.
The right-armer, who played 86 Tests for the Proteas, took 136 wickets in all formats for Surrey.
“Unfortunately, the time has come to move onto a new chapter,” he told the club website.
“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.”
Morkel was only able to play once in the Bob Willis Trophy in 2020 after being held up by travel restrictions imposed because of coronavirus and then stepping on a cricket ball before the game against Kent, resulting in an ankle injury that needed surgery.
Surrey director of cricket Alec Stewart said finding a replacement for Morkel “will not be easy”.
“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,” he added.