Paul Lambert says Aston Villa will only fulfil their huge potential with significant investment as the club looks for a new owner to take over from Randy Lerner.
The American entrepreneur, who bought the former European champions from Doug Ellis in 2006, put Villa up for sale on Monday morning, stating it is time the club found "fresh, invigorated leadership".
Lerner's future had been in doubt for much of an acrimonious campaign which ended in a lowly 15th-place finish after Sunday's 3-0 defeat at Tottenham.
Lambert said after the match that Villa had been punching below its weight for too long and that the solution was simple.
"It needs investment, it's simple. It smacks you right in the face what the team needs. That's the bottom line," Lambert said.
"I've got a lot of time for Randy [Lerner] - he's a top bloke but it's his football club and he'll decide what's going to happen.
"It's a brilliant football club, it's just too big a club to hover about where it is.
"It should be rivalling places like Tottenham and has been in the past.
"There's no doubt it's possible, the fan base dictates that. It's a huge football club and if it does get it right, it can certainly be up there."
Villa have cancelled the club's end-of-season dinner "in light of today's announcement and the disappointing end to the season".
Lambert's side were jeered by their own fans throughout the match at White Hart Lane and the Villa boss admits it's been a difficult period on and off the field.
"The magnitude of this club and with what's been going on, it's been really tough," Lambert said.
"But I said to the lads they've got nothing to be ashamed of, I'm as proud as anything of them to avoid relegation and get over that line.
"That will make them stronger because when you're in adversity and you come through it, it makes you stronger."
Lerner had bold ambitions when he secured the club for £60m, stating his intention to lift Villa back to the top of the European game.
VIlla made two trips to Wembley in 2010, reaching the League Cup final and the FA Cup semi-final, but the departure of manager Martin O'Neill shortly before the start of the 2010-11 season signalled the beginning of a decline.
Lerner's successive appointments of Gerard Houllier and ex-Birmingham boss Alex McLeish proved unpopular with the fans and current boss Paul Lambert's tenure has also come in for increasing criticism in the course of another lacklustre campaign.
Lerner said in a statement: "Several weeks back I said that following the end of the season I would clarify my future role with the club, and address what had become seemingly constant rumours of a sale.
"I have come to know well that fates are fickle in the business of English football. And I feel that I have pushed mine well past the limit."
He continued: "The last several seasons have been week in, week out battles and having now come through this last season unfortunately limping amidst very meaningful injuries and constant sale rumours, I feel further that now is the time for me to look for new ownership and thus new leadership.
"I have asked the world of Paul Lambert and (chief executive) Paul Faulkner and they have both delivered selflessly. On a personal level it is time for me, like the Shunammite, to dwell among my own and get on with other aspects of my career, following a sale.
"Above all, the debt I owe Aston Villa whether as owner, chairman, custodian or simply as a fan is to put the club first. To make good on that debt, I owe it to Villa to move on, and look for fresh, invigorated leadership, if in my heart I feel I can no longer do the job."