Tottenham manager Mauricio Pochettino said under-performing forward Vincent Janssen must do more to prove his worth at White Hart Lane.

A £17.5million signing from AZ Alkmaar in the off-season, Janssen has struggled to make an impact at Tottenham, scoring just one goal in 18 Premier League appearances, with the Dutchman yet to score from open play.

The 22-year-old Netherlands international was left out of Tottenham's squad for the Europa League defeat to Gent on Thursday.

And Janssen is no certainty to return for Sunday's FA Cup clash against Fulham after Pochettino urged his player to raise his game.

"Against Gent he was out of the squad. He needs to show more and we'll see," Pochettino said.

"Maybe he will have the opportunity to be on the bench or play [from the start]. We cannot be sure if he will be in the squad, on the bench or start from the beginning.

"Performance is always about how the players show their quality, their belief on the training ground.

"When you select the starting XI and the bench, I try to be fair. It's normal that maybe he needs to show more."