Last updated on .From the section Premier League

Ainsley Maitland-Niles, 20, broke into the Premier League with Arsenal last season

With the World Cup now but a memory, attention turns to the start of the domestic campaign.

As established stars return late to pre-season training after featuring in Russia, opportunities could arise for young players to make an impact in the early weeks of the new Premier League season.

But who are the the ones to watch?

Here BBC Sport profiles six players aged 21 or under who are looking to take the next step in English football.

James Maddison

James Maddison made his England U21 debut against Ukraine last season

Club: Leicester City Age: 21 Position: Attacking midfielder

Maddison joined Leicester City on a five-year-deal this summer, making a £20m move from Championship side Norwich City.

The attack-minded midfielder - a dead-ball specialist - impressed while on loan at Aberdeen in 2016-17, scoring a stunning late free-kick to beat Rangers.

He followed that by establishing himself in Norwich's first team last term, scoring 15 goals, including a match-winning strike in the derby with Ipswich.

Can the England Under-21 international make the step up to the Premier League?

With his technical ability, a tight turning circle and a strong goalscoring record, the evidence suggests he can.

And his manager certainly thinks so, with Claude Puel describing him as "one of the most exciting young talents in English football".

Ryan Sessegnon

Ryan Sessegnon joined Fulham as an eight-year-old

Club: Fulham Age: 18 Position: Left-back/left-winger

Introducing the 2018 Championship Player of the Year, at just 18 years old.

Despite his age, and not having played in the top flight, Sessegnon is already a well-recognised name in English football because of his athleticism, positioning and eye for goal.

The pacy winger started his career as a left-back before being pushed further forward by Fulham last season, when he scored 16 goals in 52 appearances as the Cottagers secured promotion to the Premier League after a four-year absence.

The Londoner, who has won England caps at several age-group levels, came through the ranks with Fulham, making his senior debut in August 2016 aged just 16 years and 81 days.

Speaking about him in April, BBC Sport pundit Mark Lawrenson said: "What a player he's going to be. It's frightening."

Ruben Neves

Ruben Neves was named in the 2017-18 Championship Team of the Year

Club: Wolverhampton Wanderers Age: 21 Position: Central midfielder

The Portuguese central midfielder joined Wolves from Porto last summer for what was a Championship record fee of about £16m. The 21-year-old has an excellent range of passing and calm temperament in possession.

Neves was shortlisted for Championship Player of the Year last term as Wolves claimed the title, and his stunning long-range volley against Derby demonstrated elegance and precision.

It was no fluke - all six of his goals came from outside of the box.

The midfielder missed out on selection for Portugal this summer, but Wolves fans will have been delighted to see the classy youngster sign a new five-year deal at Molineux last month.

"It is no secret that there has been interest from other clubs, but Ruben is incredibly level-headed for his age, and loves being a part of the Wolves family," said sporting director Kevin Thelwell.

Ethan Ampadu

Ethan Ampadu has represented both England and Wales at age-group level

Club: Chelsea Age: 17 Position: Centre-back/defensive midfielder

Ampadu, son of former Swansea City and West Brom midfielder Kwame, has played a role in Chelsea's pre-season campaign - starting against Perth Glory and Inter Milan.

He arrived at Stamford Bridge as a centre-back from hometown club Exeter City - having become the youngest player to represent the Grecians, a month before his 16th birthday - but is equally accomplished as a holding midfielder.

The 17-year-old earned his first senior Wales cap against France in November, as well as making seven appearances in the Blues' first team, six in domestic cup competitions.

In Gary Cahill's absence, Ampadu was picked ahead of Andreas Christensen and Antonio Rudiger to play alongside David Luiz in the heart of Chelsea's backline in their opening two friendlies, which suggests new manager Maurizio Sarri has plenty of faith in him.

"His frame, athleticism, understanding of the game and communication is great for someone so young," said former Wales manager Chris Coleman.

Phil Foden

Phil Foden scored a hat-trick to help England lift the U17s World Cup

Club: Manchester City Age: 18 Position: Attacking midfielder

Manchester City manager Pep Guardiola is a huge admirer of the teenager who tasted World Cup success with England Under-17s last October, when he was named Player of the Tournament.

Foden made 10 appearances for the Premier League champions last year, including a rare start in the Champions League last-16 home tie with Basel.

The Stockport-born attacking midfielder glides across the park. He is a proven goalscorer at youth level and performed well for City in their recent pre-season tour of the United States.

With Riyad Mahrez arriving at Etihad Stadium this summer, it remains to be seen whether Guardiola allows Foden to move elsewhere on loan to help his development.

Speaking about Foden in July 2017, after a dazzling pre-season performance against rivals Manchester United, Guardiola said: "It's a long time since I saw something like this."

Callum Hudson-Odoi

Callum Hudson-Odoi joined Chelsea in 2007

Club: Chelsea Age: 17 Position: Forward

Hudson-Odoi has won a string of trophies with the Chelsea academy, after joining the club in 2007, and the 17-year-old has impressed during the Blues' pre-season.

The forward has been deployed on the left of a front three under new boss Sarri, having started all three matches against Perth Glory, Inter Milan and Arsenal respectively, and the early signs are promising.

Despite his inexperience at senior level, the Londoner has bags of confidence and a willingness to commit defenders.

Having won the U17 World Cup with England, Hudson-Odoi made his senior debut against Newcastle in the FA Cup last term, before making a further three appearances under Antonio Conte.

Speaking after Chelsea's success in the FA Youth Cup final in April - in which Hudson-Odoi scored twice against Arsenal, coach Jody Morris said: "He's still got a lot to do but he's certainly got a chance if he keeps his feet on the ground, and matures properly, because there's a young kid there that has got a fantastic amount of talent."