Saracens number eight Ben Skirving will miss the start of the Premiership season after suffering a knee injury.
Skirving has been with Sarries since he was 14
The 22-year-old, who is in England's senior national academy squad, damaged medial knee ligaments in training and will be out for up to six weeks.
Irish hooker Shane Byrne will miss this Saturday's friendly with Rotherham with an ankle injury picked up against Gloucester on 11 August.
However, he is expected to be fit for the start of the season on 2 September.