In a major lift to Eddie Jones’ men, the powerful Saracens No8 is on course to recover from the ankle injury that forced him off at half-time against Argentina last Saturday week.
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, will be an automatic selection if fit.
“Billy is progressing really well,” defence coach John Mitchell said. “He has trained again today and we are very confident in his progression each day. He’s very likely (to be available).