England have replaced injured duo Tom Curry and Immanuel Feyi-Waboso in their 36-player squad preparing to face South Africa in the Autumn Nations Series on Saturday.
Both flanker Curry, 26, and wing Feyi-Waboso, 21, suffered head injuries in Saturday's last-gasp defeat by Australia.
Bath flanker Ted Hill and Sale Sharks wing Tom Roebuck have been called up to the training squad.
Hill, who won two caps under former head coach Eddie Jones, was previously involved in England's training squad before their opening autumn international defeat by New Zealand.
Roebuck won his first international cap against Japan in June and returns after being dropped from that training squad, although Ollie Sleightholme, who scored two tries as a replacement on Saturday, is in pole position to start.
World champions South Africa come into the game on the back of Sunday's 32-15 victory over Scotland at Murrayfield.
England have lost five of their last six matches, with all those Tests being decided by the smallest of margins.
"We're very disappointed, but it's still a tremendous opportunity against South Africa," England lock Maro Itoje said after the defeat by the Wallabies.
"We have the world champions coming to Twickenham. We have an amazing opportunity to do something.
"There's no doubt in my mind that if we do our thing, are more consistent and play smarter rugby, then South Africa is a game we can win.
"We have our backs against the wall a little bit and so it's a tremendous opportunity for us to take control of our narrative and get the rewards for our efforts."
Forwards
Fin Baxter (Harlequins), Dan Cole (Leicester Tigers), Alex Coles (Northampton Saints), Luke Cowan-Dickie (Sale Sharks), Chandler Cunningham-South (Harlequins), Ben Curry (Sale Sharks), Theo Dan (Saracens), Trevor Davison (Northampton Saints), Alex Dombrandt (Harlequins), Ben Earl (Saracens), Charlie Ewels (Bath Rugby), Ellis Genge (Bristol Bears), Jamie George (Saracens), Ted Hill (Bath Rugby), Nick Isiekwe (Saracens), Maro Itoje (Saracens), George Martin (Leicester Tigers), Asher Opoku-Fordjour (Sale Sharks), Will Stuart (Bath Rugby), Sam Underhill (Bath Rugby)
Backs
Elliot Daly (Saracens), George Ford (Sale Sharks), Tommy Freeman (Northampton Saints), George Furbank (Northampton Saints), Ollie Lawrence (Bath Rugby), Alex Lozowski (Saracens), Luke Northmore (Harlequins), Harry Randall (Bristol Bears), Tom Roebuck (Sale Sharks), Henry Slade (Exeter Chiefs), Ollie Sleightholme (Northampton Saints), Fin Smith (Northampton Saints), Marcus Smith (Harlequins), Ben Spencer (Bath Rugby), Freddie Steward (Leicester Tigers), Jack van Poortvliet (Leicester Tigers)