Portsmouth owner Alexandre Gaydamak says the club's fans may have to wait a generation before Pompey can take on the top flight's 'Big Four'.
Following a second consecutive top-10 finish in the Premier League, Pompey are looking to win the FA Cup for only the second time in their history.
"If you look at the top four clubs they have been at this level for the last 20 years," Gaydamak told BBC Radio 5 Live.
"It could take a generation, if at all, but we're in sports so we must strive."
While Portsmouth manager Harry Redknapp has plotted the club's improvement in the league as well guiding Pompey to Saturday's final against Cardiff, Gaydamak has been busy off the pitch.
And the Franco-Russian businessman, who is the son of a Russian billionaire, has grand ambitions.
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As well as investing in a new training ground, he intends to replace the club's Fratton Park stadium as he tries to challenge the Premier League dominance of Manchester United, Chelsea, Arsenal and Liverpool.
"It's the size of the big four's stadiums, their infrastructure, their financial capabilities that have put them to this level and first and foremost their talents and managers," explained Gaydamak, who took full control of Pompey in July 2006 with a £40m buy-out.
"With the exceptions of Newcastle and Spurs, which are probably maybe at the same level, most of us are in a different league as far as our infrastructure is concerned.
"First of all we have to improve our existing facilities over a generation if we want to have a totally self-sufficient organisation to be able to be at the level of the Manchester United.
"Whether we will be there I don't know, but we have to try and look at being first."
Portsmouth, whose one and only FA Cup triumph came against Wolves in 1939, go into Saturday's final at Wembley as clear favourites.
They finished eighth in the Premier League this season and boast players of the calibre of David James, Sol Campbell, Sulley Muntari, Niko Kranjcar and Kanu.
Opponents Cardiff ended the Championship campaign in 12th position but can call upon the experience of Jimmy Floyd Hasselbaink and Robbie Fowler as well as the huge potential of Joe Ledley and Aaron Ramsey.
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