It’s time to separate the men from the boys.

League Cup commitments are over for the time being, a distraction often reserved for academy graduates to stake their claims for senior squad inclusion. But now, back in the serious business of the Premier League, English football’s true protagonists and antagonists are called upon.

The division’s greatest villain, Diego Costa, will be deployed to try and sustain Chelsea’s recent dominance over London rival Arsenal; the fortunes of Manchester United in its visit from Leicester City could hinge on Jose Mourinho’s defensive selections; and Tony Pulis returns to his old club, Stoke City, to oversee West Bromwich Albion in his 1,000th managerial outing.

Here are the three things to watch this weekend:

Arsenal strives to overcome cheap Chelsea return

Arsenal has been invariably short-changed by Chelsea since 2011. In the ensuing 10 competitive fixtures since that 5-3 win for the Gunners, the Blues have conceded just two goals and taken 21 points from the 27 available in league matches.

But with eight goals plundered across Arsenal’s past two outings and the promising form of new boy Granit Xhaka, there is reason for optimism at Emirates Stadium.

Related – Marquee matchup: Gunners look to shoot down Blues’ early-season work

Whether Arsene Wenger shakes up his winning throng will be an interesting aspect. Chelsea was off the boil against Liverpool last week, and its midweek League Cup win over Leicester City still highlighted indecision and a lack of defensive leadership in the absence of John Terry. Dropping Alexis Sanchez onto the flank and putting a more physical presence up front – like Olivier Giroud – could pay dividends.

Obviously Arsenal’s centre-halves’ first task is to keep Costa quiet – both the feet and mouth of the Spaniard. The controversial striker’s theatrics managed to tempt indiscipline from Gabriel Paulista – and in turn, the red card from referee Mike Dean’s pocket – during the teams’ first meeting last season, and he’s started this term in explosive form with a league-leading five goals in five starts.

Slim picking could trouble United

While injuries to Anthony Martial and Henrikh Mkhitaryan could see Wayne Rooney slotted into the No. 10 role again – simultaneously stifling Zlatan Ibrahimovic and, most damagingly, Paul Pogba – Leicester City has a new weapon in its improving arsenal.

Islam Slimani had an emphatic beginning to his England spell last week, showing an instant understanding with fellow Algerian Riyad Mahrez and proving himself a greatly improved alternative to Leonardo Ulloa, courtesy of two headed efforts.

If Manchester United deploys Daley Blind at the back, there could be trouble. The Dutchman’s wanting height and lacking physical qualities would be highlighted by Claudio Ranieri, who could undoubtedly get Slimani to stand on the defender while Jamie Vardy busies himself feeding on scraps and anticipating flick-ons.

If Chris Smalling is preferred to Blind, expect Vardy to instead forge the most important aspect of Ranieri’s attack, as the Italian gaffer tries to rehash the breathless attacking football of last term.

It could be a fascinating tactical tussle at Old Trafford, and one that could leave early questions about Mourinho’s tenure if he oversees a third straight defeat.

Tony Pulis’ 1,000th game

Whatever you think of his defence-conscious habit of deploying centre-halves at full-back, the long throw-ins that he championed via Rory Delap at Stoke City, or his tracksuit attire, Pulis is due some praise for reaching his 1,000th match in management.

Related – Tony Pulis: Unfashionable, unaesthetic, underrated

The unabashed Welshman will fittingly oversee his West Bromwich Albion players in Stoke on Saturday, where he managed 464 games on his way to this milestone. His coaching days have seen him switch allegiances from lower-league, £25,000 journeymen like Adrian Pennock, to £13-million stars like Nacer Chadli.

“Players live a different life. They’ve been blessed,” said Pulis when asked of how the footballing landscape has changed since he took his first job at third-tier struggler Bournemouth in 1992.

“They live in a bubble and they live in a world where they get everything really. They’ve become film stars.”

If West Brom takes all the spoils in the Potteries, it could put Mark Hughes’s future at Stoke in greater uncertainty, following just one point in five matches to start the season.