Batsman Graeme Smith will not return to Surrey next season after failing to recover from a knee injury.
The former South Africa captain, who signed a three-year deal with Surrey in 2012, fractured his right knee in May.
He had an operation but has been advised by doctors that he will not be able to "fulfil the day-to-day duties of a full county season".
Smith, 33, retired from international cricket in March after 117 Test appearances.
He only played three first-class games for Surrey last season because of an ankle injury.
|Graeme Smith's South Africa record|
|117 Tests, making 9265 runs at an average of 48.25|
|197 ODIs, making 6989 runs at an average of 37.98|
|33 T20 internationals, making 982 at an average of 31.67|
This season he managed five first-class games and two Twenty20 matches.
In his eight County Championship games he scored 383 runs, including an innings of 103 against Gloucestershire at The Oval this year.
"I thoroughly enjoyed the privilege of captaining Surrey," said Smith.
"But due to my injuries in 2013 and 2014 I have been unable to fulfil my role in achieving the goals that both Surrey and I set out to accomplish when I first arrived."
Surrey director of cricket Alec Stewart paid tribute to Smith, who led the Proteas in a record 109 Tests.
"I would like to thank Graeme for the impact he has had in the time he was with us over the last two years," said Stewart.
"As a person and leader his qualities have helped lay the foundations for the progress that we all want for the club."