Ben Coad and Matthew Fisher have both gone down injured with pectoral and abdominal problems respectively.
The news comes as Yorkshire face an uphill battle in their opening County Championship match of the season against Glamorgan at Headingley, where the visitors held a 205-run advantage with six second innings wickets left going into day three.
Coad and Fisher have been plagued by injuries in recent years and neither will bowl again in this game.
The pair will be assessed ahead of Yorkshire’s next Championship match against Kent at Canterbury, which starts on Thursday.
In their absence today, last year's player-of-the-year Jordan Thompson and George Hill are acting as substitute fielders in chilly, cloudy conditions in Leeds.
Thompson was himself ruled out of this game with a calf problem but must be close to a return and could potentially come back for the Kent fixture.
Other options should Coad and Fisher be unavailable next week include all-rounders David Willey and Matthew Revis, plus South African Mat Pillans.
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