England forwards coach Steve Borthwick returned to the club he captained for six years only to see Leicester captain Ed Slater sustain an injury that may threaten his availability for the RBS 6 Nations.
Slater limped off inside the opening half-hour of the Tigers' 26-6 defeat by Saracens in an Aviva Premiership title showdown at Allianz Park and his right leg was later encased in a knee brace.
Only two weeks ago Leicester director of rugby Richard Cockerill declared that Slater - a lock who can also play in the back row - was capable of captaining England, but now his fitness must be assessed.
Borthwick, the recently appointed right-hand man to new England head coach Eddie Jones, will at least have taken comfort from the performance of Saracens locks George Kruis and Maro Itoje.
Kruis, who was mentored by Borthwick during the former England captain's trophy-laden spell at Allianz Park, was named man of the match.
The young second-row pairing were key to the dominance of the home pack, whose mastery of Leicester resulted in three penalty tries being awarded by referee Greg Garner.
One came after a line-out catch and drive and two were given during second-half scrums, the final intervention by Garner posting the bonus point for unbeaten Saracens, who have extended their lead at the summit of the Premiership to six points.
Leicester could take comfort in the performance of fly-half Freddie Burns, whose two penalties constituted their only points from the afternoon, but the recurring sight of their scrum hurtling backwards will not be forgotten in a hurry.
Evidence of Saracens' strength was seen in the 11th minute when all but two of the backline joined a line-out drive for the whitewash and when the visitors crumbled just inches from their line, referee Garner signalled a penalty try.
It was the champions' first visit to the opposition 22 and with their scrum dominating, their pack had gained a foothold early in the set-piece.
Burns' goals kept the Tigers within a point but their hopes of leaving Allianz Park with a seventh win of the season receded when back-rowers Croft and Slater departed through injury inside the opening 30 minutes.
Lachlan McCaffey and Mike Fitzgerald stepped off the bench to plug the gaps and despite the reshuffle, Leicester were standing toe-to-toe in the forward arm-wrestle while Burns expertly pulled the strings at fly-half.
Saracens would have extended their lead had Charlie Hodgson and then Alex Goode not sent routine penalties wide in the blustery conditions, but two minutes into the second half they crossed for a second time.
Once again it was a short-range line-out that provided the platform with the forwards winning clean ball and driving over, Jamie George emerging from beneath the pile of bodies with the ball.
Pressure was building on Leicester and when Billy Vunipola was held up over the line shortly after he had bulldozed through the Tigers on a separate run, they opted for an attacking scrum.
Replacement props Dan Cole and Logovi'i Mulipola were ordered off the bench for the set-piece, but the move backfired as Saracens powered over with Garner awarding another penalty try.
The last 20 minutes was the story of Saracens' pursuit of the bonus point, with the scrum their weapon of choice.
Cole was sent to the sin-bin after Leicester were shoved backwards and when Saracens were equally dominant at the next scrum, Garner waved for a third penalty try and the five-point haul was secure.