England are preparing to unleash a midfield combination of Marcus Smith, Owen Farrell and Manu Tuilagi when they face Argentina on Sunday.

Farrell is close to a return after concussion while Tuilagi is also expected to be available.

"Owen is ticking all the boxes so far," said backs coach Martin Gleeson.

"He is coming towards the end of his return-to-play so we will know very soon."

Farrell missed last week's training camp in Jersey but has been working through the 12-day return-to-play protocols after suffering a head injury against Exeter 11 days ago.

While Farrell still needs to pass the final part of the process, Gleeson says he is welcoming the prospect of fielding his first-choice midfield, adding "everything up to now has been going smoothly".

"You have Owen, who is very good at organising and good at playing at the line; Manu, who can really hit a hole, and Marcus, who is a bit of a livewire and can play what he sees and has the freedom to do that," he explained to BBC 5 Live.

"You want your best players on the park and you want the combinations on the park that will be best for England."

Tuilagi's workload is being closely managed by the England staff given his injury record, but Gleeson says the Sale centre "is all good" and is set to be available to face the Pumas.

Meanwhile, Smith and Farrell are set to resume their 10 and 12 partnership following the successful summer tour of Australia.

"They are both very, very good players, with slightly different styles but an understanding of how they can complement each other," Gleeson added.

"It's a partnership I'm really looking forward to seeing grow. We want to take [our attack] to the next level."

With Courtney Lawes unavailable because of concussion, Farrell is favourite to resume the captaincy if he is declared fit, while Ellis Genge and Jack Nowell have also assumed increased leadership responsibilities.

"There are a lot of guys who have been stepping up. That Australia tour was really good [with regards] some leaders coming to prominence," Gleeson said.

"Ellis Genge and Jack Nowell were brilliant and Courtney led us superbly.

"Owen is a leader whether he is captain or not; there are a lot of guys stepping up in that regard."

England have retained a 25-man squad to prepare for their autumn opener, with wing Jonny May included after making a remarkably fast recovery from an elbow injury.

The uncapped forwards David Ribbans, Sean Robinson and Alex Coles are all included, with at least one of the three set to make their international debut on Sunday.

England will confirm their 23-strong matchday squad on Friday morning.

England's retained squad for Argentina Test

Forwards

Alex Coles (Northampton Saints), Luke Cowan-Dickie (Exeter Chiefs), Tom Curry (Sale Sharks), Ellis Genge (Bristol Bears), Joe Heyes (Leicester Tigers), Jonny Hill (Sale Sharks), Maro Itoje (Saracens), David Ribbans (Northampton Saints), Sean Robinson (Newcastle Falcons), Sam Simmonds (Exeter Chiefs, Kyle Sinckler (Bristol Bears), Jack Singleton (Gloucester Rugby), Billy Vunipola (Saracens), Mako Vunipola (Saracens), Jack Willis (unattached).

Backs

Joe Cokanasiga (Bath Rugby), Owen Farrell (Saracens), Jonny May (Gloucester Rugby), Jack Nowell (Exeter Chiefs), Henry Slade (Exeter Chiefs), Marcus Smith (Harlequins), Freddie Steward (Leicester Tigers), Manu Tuilagi (Sale Sharks), Jack van Poortvliet (Leicester Tigers), Ben Youngs (Leicester Tigers).