Worcester Warriors head coach Richard Hill has confirmed Pat Sanderson is likely to miss the first month of the season with injury.
The 33-year-old flanker injured his shoulder during the 44-15 Championship win over Bristol in March.
Hill told BBC Hereford and Worcester: "Unfortunately, Pat's progress is still slow at the moment.
"He has seen a specialist but we don't expect to see him for at least the next four to six weeks."
Hill says the news over club captain and full back Chris Pennell is more encouraging.
"Chris picked up a rib injury in pre-season so he wasn't available for the Melbourne Rebels game," he said.
"We are hoping that he will recover fairly quickly and he should be back in a week or two's time.
"I am sure he will have seen Erri [Claassen's] performance and he will raise his game again."