Salt split the webbing of his left thumb while fielding in the county's win over Middlesex at Lord's
Sussex batsman Phil Salt is facing an uphill battle to be fit for the county's Division Two clash against Gloucestershire at Arundel, which begins on Tuesday, following an injury.
The opener underwent an operation on June 6 after suffering a hand injury in Sussex's innings victory over Middlesex at Lord's.
Sussex will now judge the full extent of the problem and a likely timescale for his return after surgery has been carried out.
A club statement read: "Phil Salt split the webbing of his left thumb while fielding on day four of Sussex’s Specsavers County Championship match against Middlesex at Lord’s on Wednesday.
VISIT THE COUNTY HUB: Your one-stop shop for English domestic cricket
"The injury requires an operation, which is scheduled to take place today (Thursday 6th June).
"The full extent of Phil’s injury and the likely timescale for his return will be assessed thereafter."
Right-hander Salt, 22, has scored 376 runs at an average of 41.77 in the County Championship so far this season.
He was also called up as Dawid Malan's replacement for England's Twenty20 match against Pakistan last month, but did not feature.
For more outstanding county coverage, try The Cricketer for three issues free this summer. Click here to sign up today
Subscribe to The Cricketer for exclusive content every day: The inside track on England's Test tour with George Dobell in Pakistan, award-winning analysis, breaking news and interviews and the only place for in-depth county coverage all year round. Plus: An ad-free app experience at your fingertips. Subscribe to thecricketer.com today for just £1.