Far from entering the unknown north of Inverness, United travel to Dingwall having drawn 0-0 at home with the team they defeated 3-0 in last season's Hampden final. Earlier this season Peter Houston's side claimed a 2-1 win at Victoria Park after extra-time in the Co-operative Insurance Cup, having faced County in the same competition last term.
The quality of the opposition is well known, too, and United first-team coach Gary Kirk said: "Any slackness at all, we could get put out of the cup."
Sean Dillon missed training on Monday after his wife gave birth to their first child on Sunday night, but his team-mates and the coaching staff discussed September's clash with County and the original tie at Tannadice.
Kirk added: "They know how hard it will be because they've all been up there.
"We've been up there a few times now in the cup and we've done all right to be fair.
"Most of them have been up their twice - they know what they've got to do on Tuesday night."