Scanlon is on-loan at Millwall for the season in the Championship.
The defender, however, is facing a spell on the sidelines with a back injury.
Scanlon has now returned to Liverpool for treatment for an injury that has hit the left-back in the past.
"He has got a stress fracture in his back, which is a recurring injury from previous," said Millwall boss Neil Harris after their 1-1 draw at QPR on Saturday.
"That is unfortunate. We’re very disappointed to lose him because he is something different from what we have already got in the squad – as a very attack-minded full-back.
“He has gone back to Liverpool to be treated in the short-term and mid-term. He is going to be rescanned at six weeks and then we’ll have a better idea whether he is going to be back soon after that or going to be an extended period.
“Anything beyond that is not a discussion at the moment.”