Hughes goes up against his former side at the Britannia Stadium on a run of just one defeat in eight games and their last home outing ended in a thrilling 3-2 win over high-flying Chelsea.
Stoke went down by the same score in their only clash with United so far this season, at Old Trafford in October, and he also takes plenty of positives from that performance when they led 1-0 and 2-1 before going down to two goals in the last 12 minutes.
Hughes said: "We will take confidence from the fact that we performed so well at Old Trafford earlier in the season.
"We scored two very good goals and were unfortunate not to see the game out. Hopefully we can do this on Wednesday and secure ourselves a passage into the next stage.
"It will be a tough game though, because United are United. They have world class players, they had a good result and performance at Villa on Sunday so they will be hoping to follow that up with another good result against us.
"It is down to us to stop them though. We know that if we play to our maximum we have a real chance of winning the game.
"We have suffered one defeat in eight, in all competitions so we are pleased with that. We are progressing well, we are improving all of the time too.
"We have a decent defensive record - six or seven clean sheets which are very satisfying too. There are a lot of positives to be taken from the past few weeks, Everton aside of course.
"If we can do what we want to do, and play to the levels that we are capable of then we will give a very good account of ourselves. We want to progress - we enjoy the cup competitions and we are in it to win it.
"It's a difficult one to gauge which United will go, because you look at their squad and they have a minimum of three very good players in each position.
"David has a lot of options, and for us it is difficult to guess what team he is going to go with. As a consequence of that, is is more important for us to concentrate on what we want to do."