Ian Blackwell's professional career could be ended by an injury, according to Durham chief executive David Harker.
The all-rounder's shoulder problem has not been resolved despite having a third operation two months ago.
"The prognosis is not good and it appears he may not be able to play to a professional level again," told Harker.
If forced to retire, he would call time on a career spanning 16 years, including one England Test cap in 2006 against India.
Blackwell, 34, began his career at Derbyshire before spending eight years at Somerset. He joined Durham in 2009, but his appearances at Chester-le-Street have been limited by fitness concerns.