Yorkshire have pulled four players out of Monday night's Vitality Blast match against Lancashire at Headingley due to concerns over coronavirus.
"The club are awaiting results of a COVID test which will determine future availability."
Yorkshire are bidding for their third Vitality Blast win of the season in a bid to keep their hopes of qualifying for the quarter-finals alive.
Willey and Kohler-Cadmore have both captained the side in the competition this season, while Fisher (eight wickets), Willey and Poysden (both five) are the county's three leading wicket-takers.
Lancashire are currently second in the table having lost only one of their first four matches.