Former Great Britain rugby league star Andy Farrell will not make his union debut this weekend because of injury.
The Saracens player, who picked up a toe injury two weeks ago, will miss Saturday's game against Harlequins as he did last weekend's against Bedford.
"It's not broken, but he won't be able to play until the soreness goes," said Saracens rugby director Steve Diamond.
Meanwhile, Lions hooker Shane Byrne is set to make his Saracens debut in Saturday's friendly at Harpenden.
The Irish international who joined the Guinness Premiership club from Leinster this summer, has been named among the replacements.
Former GB captain Farrell, 30, made his switch from Wigan Warriors three months ago.