Forwards Courtney Lawes and Jonny Hill have been ruled out of England's Six Nations opener against Scotland on Saturday.

Lawes' absence adds to England's leadership problems with regular captain Owen Farrell out for the Championship.

Prop Joe Marler has returned to training following Covid-19 isolation.

Lawes, favourite to replace Farrell as captain, sustained the head injury playing for Northampton on 16 January and has not yet passed return to play protocols.

Exeter's Hill is still struggling with a stress fracture to his lower leg and has not played since 8 January.

England are without Farrell, Jonny May and Anthony Watson for the tournament.

Centre Manu Tuilagi and flanker Sam Underhill are likely to be available later in the Six Nations once they have recovered from respective hamstring and concussion issues.

England forwards coach Matt Proudfoot has earlier said hooker Luke Cowan-Dickie, prop Ellis Genge and back row Tom Curry had all been offering leadership support to Lawes.

England's team to face Scotland is expected to be announced at 11:30 GMT on Thursday.

England squad for Six Nations:

Forwards: Jamie Blamire (Newcastle Falcons), Ollie Chessum (Leicester Tigers), Luke Cowan-Dickie (Exeter Chiefs), Tom Curry (Sale Sharks), Alex Dombrandt (Harlequins), Charlie Ewels (Bath Rugby), Ellis Genge (Leicester Tigers), Jamie George (Saracens), Nick Isiekwe (Saracens), Maro Itoje (Saracens), Lewis Ludlam (Northampton Saints), Joe Marler (Harlequins), Bevan Rodd (Sale Sharks), Sam Simmonds (Exeter Chiefs), Kyle Sinckler (Bristol Bears), Will Stuart (Bath Rugby)

Backs: Mark Atkinson (Gloucester Rugby), Elliot Daly (Saracens), George Ford (Leicester Tigers), George Furbank (Northampton Saints), Ollie Hassell-Collins (London Irish), Max Malins (Saracens), Joe Marchant (Harlequins), Jack Nowell (Exeter Chiefs), Harry Randall (Bristol Bears), Henry Slade (Exeter Chiefs), Marcus Smith (Harlequins), Freddie Steward (Leicester Tigers), Ben Youngs (Leicester Tigers)