Top-flight football has been criticised recently for its lack of entertainment value, with Jose Mourinho's Chelsea already six points clear at the top without conceding a goal in the league.
Whelan believes a salary cap would create more competition for Chelsea - who are backed by the Russian billionaire Roman Abramovich - which would in turn create more excitement for supporters.
"I would like 20 players registered with a salary cap, a figure that each team agrees on," Whelan said.
"You might get some Manchester United or Arsenal support on the basis they can see Chelsea ruining this league. Last season there was more interest in the bottom than there was at the top of the league."
Whelan told BBC Radio Five Live: "I've been advocating [a salary cap] for five or six years. If this continues then the league is over in the next four or five weeks. Manchester United have debts and Arsenal are funding a new stadium - it's Chelsea on their own.
"Good luck to Chelsea, I've got nothing against them but the competition has gone. If Mr Abramovich chooses to stay and they continue with building their squad, nobody in the league can compete with that."
Critics of a salary cap would argue the Premiership's better players would move abroad where they would be paid more, but Whelan countered: "There will be more British players in the league, which is a good thing. They [foreign teams] will follow when they see how beneficial it is."
The salary cap has been a success for rugby league, although Wigan Warriors - where Whelan is a director - were unhappy with a reduction in the cap last year.
"We were all a bit sceptical but it has worked," Whelan added.Reuse content