England rate Billy Vunipola as "very likely" to be available for Saturday's World Cup quarter-final against Australia at Oita Stadium.
In a major lift to Eddie Jones' men, the powerful Saracens No 8 is on course to recover from the ankle injury that forced him off at half-time in the 39-10 win over Argentina.
Jones names his team to face the Wallabies on Thursday and Vunipola, the only player to have started all 12 of England's Tests this year, is expected to be an automatic selection if fit.
"Billy is progressing really well," defence coach John Mitchell said.
"He has trained again today (Tuesday) and we are very confident in his progression each day. He's very likely [to be available].
"Billy is a very important player to us and a very likeable player as well. He fits well within the team.
"He loves the ball in his hand. He is very good at regaining and retaining momentum. He likes carrying the ball which is where he has his greatest influence."
While the update over Vunipola has been positive, it appears increasingly unlikely that wing Jack Nowell will play any part in the quarter-final.
Having recovered from ankle surgery and being forced to have his appendix removed, Nowell's comeback against the Pumas came at the cost of a hamstring injury that has prevented him from taking a full part in training.
"Jack wasn't at training today. He is on another prescription of training and is also progressing," Mitchell said.