Saracens have suffered an injury blow with their powerful South African prop Cobus Visagie being ruled out of action until November.
Visagie has undergone elbow surgery after suffering a recurrence of the problem he experienced while training with the Springboks earlier this summer.
Saracens rugby director Alan Gaffney said: "It is a blow, both for Cobus and for Saracens, but he needed to have the surgery and as a result is expected to miss the first two months of the season.
"With Cencus Johnston away with Samoa and Matias Aguero and Kevin Yates in with a chance of making selection for the World Cup, it could leave us a bit short of props in the early part of the season, so that is something we will have to look at resolving."
Saracens, meanwhile, have announced the signing of South African number eight Guthrie Hall, who was part of the Natal Sharks' Super 14 and Currie Cup squads this year.