Tottenham Hotspur manager Mauricio Pochettino has admitted that he is beginning to get "concerned" by Erik Lamela's injury problems.

The Argentine has been sidelined since October with an unknown issue and is no closer to having a return date despite working with a physiotherapist at former club Roma.

Lamela will undergo another scan on the problem on Friday, after which Pochettino hopes to have more information following a frustrating spell.

"Tomorrow he will have a scan. It's still difficult to give a time for him to come back. We need to wait for what happens tomorrow," he told reporters.

"There are still some problems, and we're not sure of the diagnosis. So we need to wait for tomorrow. Now we are starting to be concerned about him, because it's nearly three months and we're still in a situation with no movement.

"Today nobody advises [surgery]. It's better to wait until after tomorrow."

Lamela had scored one goal in nine Premier League appearances this season before his injury.