is unlikely to feature for England this summer after scans revealed that his back injury was worse than initially feared.
Fisher, 24, made his Test debut in Barbados in March as a late replacement for the unwell Craig Overton and took a wicket with his second ball, having John Campbell caught behind. He finished with match figures of 1 for 71 but would have been in contention for the first Test of the summer if fit, not least with a swathe of English fast bowlers unavailable through injury.
Fisher was initially diagnosed with a "stress reaction" in his back following Yorkshire's win against Gloucestershire in their first County Championship fixture this season and was expected to miss a month of cricket.
But the Daily Mail reported on Monday evening that Fisher had suffered a stress fracture and Yorkshire confirmed in a statement that he is "set for a longer spell on the sidelines" than first thought.
"Fisher's rehabilitation program has been progressing well and the club's medical staff will continue to monitor and work with the young fast bowler with his long term performance in mind at all times," Yorkshire said.
"Initially I'd said four weeks," Ottis Gibson, their head coach, had said on Sunday. "But further reports from the medical team seem to suggest that's going to be a slower process than anticipated. Because of his injury history, we're going to have to take a more cautious approach with him."
Fisher is expected to miss the majority of the 2022 summer and it is highly unlikely he will have bowled enough overs to be considered for their final Test against South Africa, which starts on September 8.
ESPNcricinfo understands that Fisher's Hundred team, Birmingham Phoenix - for whom he signed a £50,000 contract last month - have already started to look at replacement options in the expectation that he is unlikely to play any part in the tournament, which runs from August 3-September 3.
, who played for Phoenix in 2021 but was not retained and went unsigned in the draft, is understood to be the frontrunner after a bright start to the Championship season with Middlesex.