Tottenham boss Mauricio Pochettino has backed misfiring striker Vincent Janssen to improve after a faltering start to his Spurs career.

The £17 million summer signing has only scored three times this season, with all his goals coming from the penalty spot.

Janssen started Spurs’ FA Cup Third Round win over Aston Villa this afternoon, but was replaced by Dele Alli on the hour mark after failing to make an impact on the game.

However, Pochettino has backed the 22-year-old Dutch international, who scored 31 goals for AZ Alkmaar last term, to find his form in England.

The Spurs manager said: “Yes is it true [Janssen is struggling] but it is difficult for all the strikers.

“Look again at the game we played against Chelsea, both the strikers struggled in the first half- Diego Costa and Harry Kane.

“Second half I think he started to behave better and started to find better space to play but it was at a time when we decided to include Dele Alli on the pitch.

“It is always tough, not only for him. But he is very young and he has come from a different league so he needs to adapt his game.

“He needs to work hard and not be frustrated by that performance. We are a staff that is pushing a lot of the players and we will try to push him to get the level that he needs.”

Tottenham made nine changes to the side that ended Chelsea’s 13-game winning run in the Premier League with a superb 2-0 victory on Wednesday evening.

Pochettino’s team found it difficult to break down a well-organised Villa side in the first half, with the Championship outfit defending in numbers.

However, once in-form Alli replaced Janssen in the second half Spurs posed a greater threat and late goals from Ben Davies and Son Heung-Min put Tottenham into the hat for Monday’s Fourth Round draw.