It may be the EFL Cup and not the Premier League, but it’s still a London derby when Chelsea make their inaugural trip to the London Stadium to face West Ham on Wednesday night.

These two teams faced each other on the opening week of the Premier League season at Stamford Bridge with the Blues winning 2-1 courtesy of a late strike from Diego Costa. But that match seems like it happened ages ago, as both teams’ fortunes have gone in vastly different directions.

Chelsea kicked on from that opening day victory, winning six of their first nine fixtures, with a small blip over a two-week period resulting in defeats to Liverpool and Arsenal and a draw away to Swansea.

West Ham have gone in almost the complete opposite direction, collecting just three points from their first six Premier League matches and putting pressure on West Ham manager Slaven Bilic. However, the Hammers have reversed their fortunes, going unbeaten in their last three and will look to build on that momentum with a win in a derby.

Both Bilic and Chelsea manager Antonio Conte have acknowledged the importance of the derby and have said they will play strong teams on Wednesday. Both sides can afford to do so, as neither one is involved in European competition. But the real question is how strong those sides will be.

For Chelsea, Branislav Ivanovic and Cesc Fabregas are ruled out due to injury, but John Terry looks to return to the squad for the first time since picking up an ankle injury over a month ago in the draw against Swansea.

What Terry’s role will be should be a talking point, especially with Chelsea switching to a back three. Where Conte deploys him in that back line should give an indication of his plans for Terry going forward.

West Ham’s team selection should also be interesting, since Bilic in the last two weeks has unveiled his own system featuring a back three. The Hammers haven’t looked quite as comfortable with it as their opponents on Wednesday night, but it has solved their defensive woes from early in the season.

It’s likely that Bilic will play a similar team to the one that featured against Sunderland, with Michail Antonio pushed forward into a more natural wing back/wide midfield position and Manuel Lanzini and Dimitri Payet behind a lone striker.

If nothing else, it will give the Hammers another opportunity to get adjusted to their new system, but also give them a chance to claim a big scalp that could lift the team’s confidence in Premier League matches going forward.