Dean Smith has insisted Jack Grealish will not be sold on the cheap if Aston Villa lose to Derby County in the Championship play-off final.

Tottenham are likely to revive their interest in Grealish if Villa fail to seal a return to the Premier League at Wembley on Monday. But Smith pointed out his captain signed a new five-year deal in September and warned potential buyers it would take a sizeable bid to prise the midfielder from Villa Park.

“He’s signed a brand-new contract at the start of the season, committing himself to the football club,” Villa’s manager said. “He loves Aston Villa and he’ll want nothing more than to get promoted with Aston Villa. If we don’t go up he’ll cost someone a hell of a lot of money if they want to buy him. He is committed to Aston Villa and we’ve not even spoken about it otherwise.”

Smith will find it significantly easier to keep Grealish if he masterminds victory over Derby, given estimates that the final will be worth £170m to the winners. However, while Villa will no longer be entitled to parachute payments if they are still a Championship club next season, Smith is confident there will not be a repeat of the financial problems that followed defeat in last year’s final by Fulham.

Villa faced an uncertain future after a tax bill in the region of £4m went unpaid, only for their money problems to ease when Nassef Sawiris and Wes Edens bought majority control from Tony Xia last summer.

Financial fair play regulations state Championship clubs are not permitted to lose more than £39m over a three-season period, but Smith believes a club of Villa’s size have to think ambitiously.

“The potential is massive,” he said. “We all know the financial turmoil the club was in but we’ve got new owners who have got big ambitions, not just for the first team but for the academy as well. The restrictions that come with the EFL make it tougher but if you’re in the Premier League the potential for this club is great.

“You have to prepare for winning or losing. One way or another, on Monday night we will either be a Premier League team or a Championship team and you have to have two scenarios for it. But the difference this year is that the owners are fully behind the club and it’s on an even keel and hopefully moving in an upwards direction.”

Smith said there will not be added pressure on Grealish, a boyhood Villa fan and the team’s talisman, to play well against Derby. “That is something right from the off we have played down,” the former Brentford manager said. “It is not about one person or pressure, it is about the team. If players perform as a team you have more chance. It is not down to Jack Grealish. Yes, Jack Grealish has got that little bit of brilliance but so has John McGinn and Tammy Abraham, [Anwar] El Ghazi and Tyrone Mings.

“We won’t put any pressure on any individual and talking to Jack he doesn’t feel that either. He has relished being the captain of Aston Villa and is looking forward to the game and hopefully getting that win.”