London - Breaking into the Premier League's top six has been a tough task for the teams outside the elite group of Manchester City, Liverpool, Tottenham, Chelsea, Arsenal and Manchester United.
But with questions over United, Arsenal and Chelsea, there could be a rare vacancy to fill this season.
Here the three clubs most likely to upset the established order:
Since their fairytale Premier League title in 2016, the Foxes have finished 12th and then ninth twice, but boss Brendan Rodgers heads into his first full season at the King Power Stadium hoping to crack the top six.
Even the sale of England defender Harry Maguire to Manchester United for £80 million ($97 million) cannot sap the optimism around Leicester, who showed in a 3-0 demolition of Arsenal late last season that they have nothing to fear from the so-called big guns.
Jamie Vardy remains the key to Leicester's success, with the striker's superb finishing and clever movement bringing 18 goals in 34 league games last season.
Former Liverpool and Celtic manager Rodgers, hired in February, has tried to surround Vardy with more quality, bringing in Newcastle forward Ayoze Perez and turning Belgian midfielder Youri Tielemans' successful loan spell from Monaco into a permanent move.
Tielemans should dovetail well with promising playmaker James Maddison to increase the supply lines to an attack that could also feature young forward Harvey Barnes, while Ben Chilwell and Ricardo Pereira are two of the better attacking full-backs in the Premier League.
Nuno Espirito Santo's side finished closest to the top six, ending up in seventh place after an impressive first season back in the top-flight.
While Wolves' rapid progress under Nuno is undeniable, they were still nine points behind sixth-placed Manchester United and need to make further strides to overhaul them.
With that in mind, Wolves sealed permanent deals for Raul Jimenez, who netted 13 times in the Premier League last season, and Leander Dendoncker after their loan spells, while Italy striker Patrick Cutrone arrives from AC Milan.
Wolves enjoyed wins against four of the top six and knocked Liverpool out of the FA Cup, but now Nuno has to work with the added demands of the Europa League.
That could prove an especially vexing issue given the manager so desires a settled side that 10 of his players made at least 33 Premier League appearances last season.
Everton have been knocking their heads against the Premier League's glass ceiling, finishing seventh, eighth and eighth over the past three seasons.
But Marco Silva's side head into the new campaign with renewed belief they can bridge the gap after Everton won five of their final eight matches, including home victories against Chelsea, Arsenal and Manchester United.
Idrissa Gueye and Kurt Zouma have departed since last season, the former to Paris Saint-Germain and the latter back to Chelsea after his loan.
But Silva has brought in Juventus's gifted young striker Moise Kean, Manchester City defender Fabian Delph and Mainz midfielder Jean-Philippe Gbamin and can also look forward to more progress from Brazil forward Richarlison.
Billionaire majority shareholder Farhad Moshiri has laid the foundations for Everton's future by backing plans for a new stadium and funding significant investment in new signings -- now Silva has to build a team fit for that arena.