Fresh off the back of a 1–1 draw away at Ross County, United can reach Hampden with a win in their next match.
Glenn Middleton particularly impressed in Dingwall, posing a constant threat down the left wing and setting up Tony Watt for the equaliser just after the hour mark.
However, Fox knows Saturday’s performance cannot be a one-off from Middleton or any other member of the squad if he is to lead the side to Scotland’s national stadium.
“Glenn has been great – he’s a fantastic boy to work with, really positive,” he said.
“He sets up the goal for Tony, which will do his confidence the world of good, and he’ll be an important player going forward for us.
“On his day he’s a very, very good player – that’s the reason we brought him to the club.
“I would like for every individual through the whole team to find that level of consistency. It’s not easy to do, especially with wingers, but he was good today.
“We now move on to Tuesday which is a huge game for everybody at this football club. It’s an opportunity to move on to Hampden. It won’t be easy, but we’ll get them recovered and ready.”
Staggies manager Malky Mackay, though, will have to contend with the loss of left-back Ben Purrington for the foreseeable future after the defender went off injured.
If the 26-year-old’s issue is serious, it threatens to open up a gap in the County defence with Connor Randall not yet back in full training and Ben Paton – who filled in at left-back last season – also nursing a knee issue.
However, there is some good news for Mackay as Purrington’s fellow summer recruit George Harmon could return to fill the void.
“Ben has opened up his ankle, he’s in a boot and we have to wait and see,” Mackay said.
“It looks like it’s not something that can be brushed off in the next week or so.
“George Harmon is back training again, which is good. Ben Paton has had a knock to his knee, which we’re hoping will be okay, and Connor Randall is a couple of weeks away.
“George being back is timely but I’m disappointed for Ben because I’ve thought over the last couple of weeks he has really started to adapt.”