Alan Solomons' men have lost two of their last three league matches, including last time out to Zebre.
Yet their form on the continent has been strong, with three wins from three, leaving them on the brink of qualifying for the knockout stages.
And as London Welsh player/coach Ross, who spent two years at BT Murrayfield Stadium, leads his team against Edinburgh for a second weekend in a row, he is wary of the threat they pose.
"Edinburgh are in a good position. They've won in France and if they beat us down here they'll deserve to progress," he told the Edinburgh Evening News.
"To win your first four matches would be a pretty good position to be in.
"Edinburgh are well drilled and know what they are doing.
"There's a pretty good structure to their game and I'm sure they will enjoy their Christmas games against Glasgow as well.
"If they can turn us over it will put them in a pretty good position."
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