And Robinson had further cause for concern when Wasps back Josh Lewsey limped out of his team's narrow success against Castres due to a hamstring problem.
Both Cueto and Lewsey appear certain starters when England tackle New Zealand at Twickenham on November 5, with Robinson due to name a 30-man squad.
Wasps were the only winners among England's six Premiership clubs, edging out Pool One opponents Castres at Adams Park thanks to a Paul Sackey try, 11 points from Jeremy Staunton and a late Mark Van Gisbergen penalty.
It was hardly a vintage Wasps display though, and they will require a significant improvement in next Saturday's encounter against French hosts Perpignan.
Leicester's 26-game unbeaten home record was halted by reigning European champions Munster, who triumphed 21-19 at Welford Road, while Northampton lost 22-10 in Biarritz following earlier defeats for Sale, London Irish and Gloucester.
In contrast, Celtic nations Ireland, Wales and Scotland produced seven victories from eight starts, with Ireland's trio of teams all winning and the Welsh contingent of Llanelli Scarlets, Cardiff Blues and the Ospreys also completing a clean sweep.
Leicester, Heineken Cup winners in 2001 and 2002, face an uphill struggle to qualify from Pool Four after Ronan O'Gara kicked a late long-range penalty to secure Munster's ninth successive tournament win against all opponents.
"We have just got to dust ourselves off and deal with this defeat before going to Cardiff next week," said Tigers head coach Pat Howard.
"After all, Munster were in this same situation last season after they lost their opening game to Sale."
"Winning on the road is one of the hardest things to do in this game," said Munster captain Paul O'Connell.
"And winning at Welford road, one of the toughest grounds to visit, is great, but we are still a long way off our best."