Sussex and England wicketkeeper Matt Prior will have his long-standing Achilles injury assessed by the England & Wales Cricket Board.
The 33-year-old, who has not played since the second Test against India in July 2014, has no date set for a return to action.
"It is sad for Matt really," Sussex manager Mark Robinson told BBC Sussex.
"It is a bloke's career - something he has done since 18 - and it has been threatened. Our thoughts are with him."
Prior, who has 79 Test caps, had surgery on his Achilles tendon in September and his recovery had been expected to take four months.
But the South Africa-born right-hander, who lost his central contract last year, is now out indefinitely.
|Matt Prior's England career|
"He is really battling with the Achilles," added Robinson. "He has gone to see the ECB to see what the latest situation is and what can be done.
"From a club point of view, it is not great either. We thought we were getting a world class wicketkeeper-batsman in our top five, keeping wicket and balancing our team. Obviously that is gone.
"We'll have to just wait and see what comes out in the next couple of weeks."
Meanwhile, Robinson has confirmed fast bowlers Jimmy Anyon and Lewis Hatchett will be sidelined until at least the middle of May because of injury problems.
"It really stops our ability to rotate and have that competition you want in your seam department," he said.
"Jimmy has been out for a long time and is desperate to play. Lewis hurt his back in February and has had a couple of aborted attempts at a comeback. It makes us thin on the ground."
BBC Sussex are hosting a Sussex cricket special on Friday, 10 April at 18:00 BST. You can listen on FM frequencies, DAB or via the BBC iPlayer.