Sean Maitland became the latest Scotland player to suffer an injury as Saracens slumped to back-to-back Premiership defeats for the first time in two years with a 31-23 loss at Gloucester on Friday.
Sarries were surprisingly beaten at Worcester Warriors last Saturday and the champions still trail leaders Wasps - who have a game in hand - by five points after suffering another setback at Kingsholm.
England prop Mako Vunipola came through 70 minutes on his return from a knee injury, but a Billy Twelvetrees penalty and Richard Hibbard's try in the closing stages ensured Gloucester claim the scalp of the European champions.
There was also more concern for Scotland when wing Maitland was withdrawn early in the second half due to what appeared to be a rib injury, with head coach Vern Cotter having already lost Gloucester scrum-half Greig Laidlaw and Josh Strauss for the rest of the Six Nations.
Vunipola played a hand in a brilliantly worked Schalk Brits try in the opening 10 minutes, but the home side led 16-13 at the break courtesy of a Tom Marshall score and 11 points from the boot of Billy Burns.
Jeremy Thrush punished some uncharacteristic Sarries mistakes to go under the posts and Burns converted before leaving the field on a stretcher after suffering an injury while making a tackle.
Will Fraser's converted try brought Sarries level at 23-23 midway through the second half after Paul Doran-Jones was sin-binned, but Twelvetrees was successful from the tee and Hibbard gave Gloucester breathing space.