As the new Premier League season gets underway, there will be a few members of the so-called ‘big six’ nervously looking over their shoulders.

With Liverpool and Manchester City likely to slug it out again at the summit of the table, there will be a dogfight behind them for the remaining two Champions League spots.

This season though, there may more than just the four sides battling it out for a place in Europe’s top competition.

Wolves, Everton, Leicester and West Ham have all invested heavily and intelligently in the summer, meaning this could be the season that the ‘big six’ is finally breached.

Wolves came the closest to bridging the gap last season, as they finished seventh on their return to the Premier League.

Nuno Espirito Santo’s side played some eye-catching football, and proved to be a difficult game for the big sides – Arsenal, Tottenham, Chelsea and Manchester United all suffered defeats at the hands of the 2017-18 Championship winners.

They have not rested on their laurels this summer though. Striker Raúl Jiménez, who scored 17 goals for the club last season, joined on a permanent deal for £34.2million. This was a significant coup for Wolves, and a signal of intent for the upcoming season.

Former loanee Leander Dendoncker also completed a permanent move, before highly-rated Italian striker Patrick Cutrone joined from AC Milan. Cutrone, 21, scored 27 times in two years at AC Milan, and will provide another option up front.

Youngsters Pedro Neto and Bruno Jordao also joined from Lazio, while Real Madrid centre-back Jesús Vallejo joined on loan as defensive cover.

Wolves’ summer business added depth to an already strong squad, as well as young talent that will shape their future. After another season in the Premier League, Santo’s side will only improve, and could challenge the likes of Chelsea and United for the remaining Champions League spots.

Everton were a side that lacked consistency last season, but after year under Marco Silva, they will hope to produce more attacking performances like the 4-0 win over Manchester United in April.

Andre Gomes, who was a standout performer last term, joined permanently from Barcelona in the summer, while the departing Idrissa Gueye was hastily replaced by the £22.5million Jean-Philippe Gbamin.

The Merseyside club then spent over £50million to bring in Alex Iwobi and Moise Kean from Arsenal and Juventus respectively, highlighting the club’s ambition and power to compete in the European transfer market.

Fabian Delph and Djibril Sidibe could also prove to be savvy signings, as Everton look to build a squad that combines youth with experience.

If Kean can become the goal scorer Everton have been missing ever since Romelu Lukaku’s departure, Silva’s side will find themselves competing with the very best in the league.

Leicester will begin their first full season under Brendan Rodgers full of confidence. The Midlands side looked markedly better after the Welshman took the reigns in February, and their fans will hope they can start turning attractive football into consistent results.

The permanent signing of Youri Tielemans for £40million looks to be a bargain after he contributed to eight goals in 13 games, while on loan from Monaco.

The ageing Danny Simpson was replaced by the youthful and energetic James Justin from Luton Town, while Dennis Praet’s move from Sampdoria provides Rodgers with added midfield options.

Ayoze Perez, a proven Premier League striker, signed from Newcastle for £30million and will look to share some of the goal scoring responsibility with Jamie Vardy.

After heavy investment, Rodgers will see seventh place as minimum. His side have the potential to reach the top six, but the new signings must integrate quickly and buy into his style.

West Ham have also splashed the cash this transfer window, breaking their transfer record to sign Sebastien Haller from Eintracht Frankfurt for £36million.

Haller is a presence up front, standing at six foot two, and managed 15 goals in the Bundesliga last season, as well as nine assists. Hammers fans will hope the Frenchman will be the answer to their long-standing striking issues.

Haller will get chances too, with Manuel Pellegrini also bringing in Spanish creative midfielder Pablo Fornals from Villareal.

With Manuel Lanzini and Andriy Yarmolenko also returning from long-term injuries, they will almost have the effect of new signings, and West Ham’s midfield may be unrecognisable from the end last season.

With the addition of Haller and Fornals, West Ham have an incredibly strong core, with the ever-improving Declan Rice playing in front of the imperious Issa Diop.

Pellegrini will know he will need to improve on last season, and staying in touch with the top six would be a step in the right direction.

All these sides certainly have the tools on paper to challenge the big sides in the league after this summer transfer window, but new signings don’t always fit in as well as planned.

Perhaps the side that gets the closest to sixth place, will be the team whose new players settle the best.