Yorkshire have confirmed that Ryan Sidebottom is expected to be out of action for "several weeks" after he injured his calf in the club's opening County Championship fixture.
The 37-year-old bowler picked up the problem while batting in the victory over Worcestershire, and the champions are now set to be without another experienced seamer ahead of the trip to Trent Bridge to meet Nottinghamshire on Sunday.
"He is likely to be missing for several weeks," director of cricket Martyn Moxon told the county's website.
"He is set to have a scan in the next day or so and once we have the results back we will have a better indication of how long he'll be missing."
Yorkshire are also currently without Liam Plunkett, who is touring the West Indies with England.