Watford boss Marco Silva says he is not surprised by Eric Dier's emergence as a key player for club and country after working with the Tottenham man at Sporting Lisbon.

Dier, 23, moved to Portugal as a child and came through the ranks at the Primeira Liga giants before returning to England in 2014 when he was signed by Spurs.

Since then he has established himself as a key part of Mauricio Pochettino's plans and captained England in last month's friendlies against Germany and Brazil.

While Silva took over at the Estadio Jose Alvalade just three months before Dier's move to Tottenham, the midfielder said his new coach was "fantastic" for him during that time.

Silva, who followed Dier to England by taking the job as Hull City boss last season, was left as equally impressed by the player he saw begrudgingly depart.

"When Eric was with me, I saw since the first day that he was an amazing boy in that moment, one player with fantastic skills," he said.

"For me it is not a surprise what he has achieved at Tottenham and what he has achieved with the national team as well.

"In that moment he was a big miss for me at Sporting when he left in the pre-season, I tried everything to keep him at Sporting because he would have been a really important player for me and my ideas but at the moment he had a dream to come to Tottenham and the Premier League."

Silva - whose Watford side welcome Dier's Tottenham to Vicarage Road this afternoon - believes Dier has improved since moving to England and thinks he benefited from coming through the academy of a foreign club.

"I'm happy because he has improved a lot his football," he added.

"He proves every day and with Tottenham and the national team how good a player he is and I am happy because not only is he a good player, a fantastic player he is a very good boy as well and a very good professional.

"I think you don't have a lot of examples like Eric. Maybe he is the only one to start really early in Portugal at Sporting but after he came here.

"I think it is important for him and he has said every time that the moments he was in Portugal were really important for him to grow up and understand better some important things in football."

Watford go into the game knowing a victory would take them level on points with seventh-placed Spurs.

They will be without midfielder Will Hughes after he suffered a hamstring injury in Tuesday's 4-2 defeat to Manchester United.