Manchester United midfielder Ander Herrera could face weeks on the sidelines with a thigh injury and is expected to miss Saturday's FA Cup clash against Huddersfield, the Sun have reported.
The Spaniard must wait to see how the injury responds to treatment before being given a fixed return date.
Manager Jose Mourinho has confirmed that Herrera has joined striker Marcus Rashford on the list of absentees.
"Injured, both," said the Portuguese coach. Asked if they were expected to face a long spell out, he added: "I don't think so. Let's wait a little bit because when it is little ticks and muscles you never know until you know for sure. It's not possible today."
Both players missed last weekend's 1-0 defeat against Newcastle, which left United 16 points behind Premier League leaders Manchester City.
Herrera has seen his game time significantly reduced this season, falling behind Paul Pogba and Nemanja Matic in the pecking order.
The 28-year-old, who was last season named the club's player of the year, would likely have been included against Huddersfield.
He has been linked with an exit in the summer, with Serie A club AC Milan believed to be interested.
United are expected to demand over £30m for Herrera and will look to replace him with one of a number of targets, including Nice's Jean Michael Seri.
The former Athletic Bilbao man has made 19 appearances in the Premier League this season, although eight of those have been starts.