The Brazilian seems likely to miss the trip to Craven Cottage, having been substituted at the break due to injury during United’s 3-0 Carabao Cup defeat to Newcastle United on Wednesday.
“I can’t give an answer on that,” Ten Hag replied when questioned on the severity of the issue.
“We have to wait 24 hours, but I think definitely for Saturday, he is out.”
There are also question marks around Raphael Varane, who didn’t feature in the matchday squad against the Magpies due to illness.
Aaron Wan-Bissaka returned to first-team action for the first time since 16 September, replacing Diogo Dalot to boost Ten Hag’s options in a backline which is still missing Tyrell Malacia, Lisandro Martinez and Luke Shaw.