Yorkshire fast bowler Ryan Sidebottom could miss Saturday's Division One clash with Northants because of a hamstring injury.
The former England star suffered the injury during the Roses match with Lancashire and underwent a scan on Wednesday.
Yorkshire coach Jason Gillespie told Yorkshire's official website: "We're hoping there's not much there, and it's certainly not a long-term injury by any stretch.
"We're hopeful he'll be back sooner rather than later. We're hoping he'll be back very soon.
"If the scan comes back and there's something there, it won't be a long-term injury.
"If someone does a hamstring properly, they are out for four weeks. We're certainly not anticipating anything near that. Northampton will possibly be too soon, but Sid will travel with us and get treatment there.
"We're pretty confident he'll be ready for the next game. We don't anticipate it to be a long time."