The Steelmen struggled to make their mark on the game in the Highlands with their hosts eventually cruising to a comfortable win with goals from Ivan Sproule, Richard Brittain and Iain Vigurs.
Following their emphatic 3-0 victory over Inverness Caley last weekend, Well had the opportunity to build up a gap between themselves and the chasing pack as they look to secure European football for the second time in as many years.
But as a consequence of Saturday's defeat, Well have slipped one place from second in the SPL and back into a tight pack where only five points separate second- top from ninth.
And the Fir Park gaffer has called on his players to step up to the mark once again, before all of their hard work this season is undone. He said: "I'm disappointed and we need to get our heads right and look towards Wednesday night (against Celtic).
"You can't always guarantee good football or great play, but what you have got to guarantee is that you can run and work as hard as your opponent, do all the dirty bits which Ross County did. From my point of view, we can't accept another performance like that.
"We've done well, we're pleased with where we are at the moment, but there's still about a dozen games left and we've got to dig deep and get back to winning ways as soon as we can."
It wasn't as much the defeat but the nature of it that will cause the most concern for the clutch of Motherwell fans that made the trip up the A9 on Saturday.
Their side struggled to deal with the physicality of their hosts, as well as the heavily-sanded surface, from the outset. Attacks down the flanks through Henrik Ojamaa and Chris Humphrey proved fruitless in the bogged down and bobbly pitch, as focal point Michael Higdon struggled to make his presence felt against a resolute County defence.
Well were also culpable at the back as County carved open the defence for the first, while affording time and space for Brittain and Vigurs to pick their spot in the second half.
Next up for McCall's men is the visit of Celtic to Fir Park on Wednesday night, followed by a trip to Tynecastle three days later. There's no denying the size of the task facing Well if they are to try and halt their stuttering form in two days' time, but the manager is hoping a number of first-team regulars who were missing in action on Saturday can aid their cause.
McCall added: "I thought Ross County wanted it more, they played the condition of the pitch far better than us, and just all over the park they were hungrier, and that's not what you want to be saying as a manager."