Barnsley FC's head coach and chief executive are both confident the Reds can compete well in the Championship next season if they beat Millwall in the play-off final.

Johnstone's Paint Trophy champions Barnsley are back at Wembley for a second time this season for a 3pm kick-off on Sunday. Victory would cap an astonishing comeback after they were bottom of League One at the 20-game mark and would also place them in the same division as Aston Villa and Newcastle.

The Reds – who were relegated in 2014 – are expected to gain around £6million if they get promoted while they could also rake in several further millions from the potential sale of their former player John Stones due to a sell-on clause. Even then, they would still have one of the smallest budgets in the second tier.

"Of course we can compete in the Championship," chief executive Ben Mansford told the Chronicle.

"Let's not underestimate the size of the challenge, it will be considerable. The financial make-up of the Championship has changed dramatically even in the two years since we were relegated with the increased television deal and other factors. It will be a challenge but it's a challenge we will embrace and look forward to. We've tried to sign young hungry footballers who care passionately about Barnsley.

"We believe we have a set of really talented young men who will give everything in the Championship. Let's see where that might take us – but first and foremost we have a very difficult game against a good Millwall team."

Caretaker head coach Paul Heckingbottom agrees that the Reds are more than capable of surviving in the Championship should they beat Millwall. Heckingbottom said: "I 100 per cent believe that, if this group stays together and we add a couple of players, that we can stay up. That is because we've got togetherness, commitment and a good way of playing so every team will have to be at their best to beat us even if they have more quality than us.

"We're the club that has spent the longest time in the second tier but the Championship has moved on a hell of a lot. The money is getting more and more and we have to get on that bandwagon.  If we go up we'll be the smallest team, with the smallest budget but that will still be a big improvement from where we are. If we get an extra £6million from going up then we have to invest that in the right areas of the football club so we are in a better place.

"We'd fight tooth and nail to stay in there but you have to make decisions which mean that, if you go down, you're in a better position to go back up.  We'll be closing that gap bit by bit and we have to be of that mindset unless someone with millions of pounds came and bought us, which isn't happening."

Mansford is confident the Reds could keep the majority of their stars players if they are promoted but adds that the task would be more difficult should they lose on Sunday. He added:  "Patrick (Cryne, club owner) has said that, if we got promoted, we wouldn't be under any financial pressure to see any players move on.

"If we stayed down then the quality of player we've recruited and quality of performance they have put in will undoubtedly attract attention. We know about that, we're not naive. But we have to do what is best for Barnsley Football Club.  That's what we'll be focusing on when we find out what league we're in and when we find out what interest there might be in our players."

Heckingbottom – whose own position is expected to be made permanent in the coming weeks – added: "We've got a lot of our better players under contract for next year. No one can slide out on the cheap.  Being in a different league will change the situation for the club and the players.  But, if we go up, I can't see any reason why someone wouldn't want to be involved in what would be an even bigger challenge than getting promoted."