Willis was driven from the field on a medical cart in the 66th minute on Saturday after Sebastian Negri rolled him out of a ruck, forcing a cry of pain from the Wasps back row that echoed around the empty stadium as his leg twisted awkwardly.

It was a cruel blow for Willis, who shortly before had scored his second international try but is now set for a lengthy spell on the sidelines.

"We're all concerned. He's on crutches. He'll be examined tomorrow (Sunday) but obviously it didn't look good and probably isn't good," Jones said.

"We'll just wait and see. He's got some sort of knee injury and has been in the dressing room with us."

Willis was named in England's squad for their 2018 tour to South Africa but had to withdraw because of a serious injury to his right knee, before his career endured the additional setback of a significant ankle problem.

Negri, the Italy flanker, was on the ground when he performed a controversial manoeuvre called a 'crocodile roll' that while yet to be outlawed from the game, is a source of tension in the game.

"It's up to the referee to interpret that. The referee has to make the decision on whether it was safe or not. We abide by whatever decision the referee makes," Jones said.

Australian Associated Press