The wingback has been ruled out for at least six weeks – but club medics are hoping rest and non-invasive treatment of the ACL injury will see him return to action in the New Year.
That could still be the case – but his reaction to initial treatment has fuelled hopes surgery can be avoided.
Thomas Tuchel confirmed: “Ben is out, he has a partial injury of his ACL, and the decision is to treat it conservatively.
“The next six weeks will tell the story if he makes it and will be available or if he will need surgery.
“He is actually very positive, I spoke to him a few minutes ago. His body has reacted positively to the first treatments. After a while you have to refocus and focus on the positive things which are the next weeks and do everything that is possible so that he can get back on the pitch and help us again.”