Neil Lennon is ready to put his skipper straight back into the starting line-up for the quarter-final following the end of their 20-game winning run at Aberdeen last weekend.
The Parkhead boss has total confidence his side can put that disappoint-ment behind them, and get back on with the job of winning the seven points and four cup-ties that will give them a Treble.
Lennon said: "While our winning run came to an end at Aberdeen, our unbeaten run has not, and it was another point gained in the championship.
"So we are in a far better position than we were, say, a month ago."
That's because Celtic are four or five games and several points nearer their goal. Lennon can sense the desire to get back into the winning groove, and said: "I don't see why we can't bounce right back.
"We're disappointed at drawing with Aberdeen, and it has been a long time since we felt anything like we did after the game on Saturday.
"But we have got huge games coming up and we're very motivated to go on and win them.
"We will have all of our big players back, all the international boys will be involved this weekend, so it will be a pretty strong team.
"There are no injuries among those who have now come back, and Scott Brown should also be fine for Sunday."
The presence of the captain could be key against a United side Lennon expects will try to get into the faces of the Celtic players to disrupt their rhythm, in the same way Aberdeen did last weekend.
Lennon acknowledges what a major hurdle this represents in their charge for silverware, and needs no reminding Peter Houston's side have already knocked Rangers out of the cup.
"Dundee United have played some good football of late, and they seem to come on strong in the second half of the season," he said.
"It will be a very difficult game, but it should be a cracking game. Again, the draw has done us no favours, being away from home to one of the better teams in Scotland.
"It is has become a bit of a joke, really. But we will be doing our best to go there and to win the game. We have until Sunday to prepare, and, hopefully, the boys will have a good week. They will be ready to go."