Coventry, in 8th, host Hull City, three points ahead in 7th, on Wednesday night but Robins said: “You have got to be realistic – it will come really quickly.
“While they will be ready mentally, physically [Sunday] will take a toll. We said it to them in the dressing room, it’s really difficult because you are so close to a Wembley Cup Final and you’ve missed out on a penalty shootout again, a lottery.”
City also suffered a shoot-out defeat at the hands of Luton Town in the Championship play-off final last May and Robins added: “It would be nice to get back to Wembley again, every time you come you’re a bit more comfortable, you’ve got that experience to draw upon.
“If we can get back this season, happy days. We’re not giving up on it but it will be really difficult because we have four games left and we have got to win them all.
“We’ll have a real go, I’ll give them a day off because that’s a lot of energy expended, and we’ve got to make sure we come back on Tuesday with the right mentality to go again.”
Robins spoke of his pride at the performance which took United all the way at Wembley and said: “If we go into games with that belief we’re a real threat to any team, there’s no doubt, it just shows you what we are capable of.”