Liverpool manager Jurgen Klopp has revealed that Jordan Henderson is a doubt to face Plymouth Argyle in the FA Cup on Sunday.

Henderson limped off in the second half of his side's 1-0 win over Manchester City on New Year's Eve with a heel injury, which also forced him to miss this afternoon's 2-2 draw with Sunderland.

Klopp admitted that he is unsure about the full extent of Henderson's injury, but expects his captain to miss this weekend's third-round clash at Anfield.

"I don't know [how long he will be out for] exactly. Hopefully it's not too serious, but the FA Cup will be difficult," he told reporters.

Henderson had previously started all 19 of Liverpool's Premier League games this season.