Everton boss Frank Lampard has insisted that Dele Alli can "absolutely" rediscover the incredible form he showed in his peak years at Tottenham, despite his recent struggles at Goodison Park.
Alli emerged as one of the top young players in Europe during the early stages of his career at Spurs, and helped them become top-four regulars while also earning a regular spot in England's national team set-up.
The midfielder was unable to maintain that high level, though, and after two-and-a-half seasons of mediocrity, Spurs cut their losses and accepted a bid from Everton in the January transfer window.
What has Lampard said about Alli?
Alli has since made only seven Premier League appearances for the Toffees, including just one as a starter, and it has been suggested that his best years are now firmly behind him.
However, Lampard is not yet ready to give up on the 26-year-old, who he believes is capable of maturing into a more well-rounded player over the next few seasons.
Asked if Alli can still be the player he once was ahead of Everton's Merseyside derby clash with Liverpool on Sunday, the head coach told Sky Sports: "Yeah, because we've seen it. It's a challenge because there has been a period when he hasn't been at those levels, he'd be the first to say it. I say it to him a lot - that is the challenge.
"Work, consistency, training, preparation and all those things can absolutely get him back to where he was. I believe that, otherwise I wouldn't have brought him to the club. It was never going to be an overnight story because that isn't football and it's not life as far as I'm concerned.
"Sometimes you have to fight, people have setbacks, issues, tough moments - we all have them in our own ways and Dele can know I'm very much with him on that.
"All the questions will be answered by him. No doubt that talent is there and maybe with more years and maturity, that talent comes back and so does maturity and then you see a slightly different Dele, but the same level of quality."
Lampard admits Everton must be 'faultless' to beat Liverpool
Everton are sitting 17th in the table at the moment, one point above Burnley having played a game more, with the relegation battle now heating up heading into the final weeks of the season.
Lampard's side beat Manchester United 1-0 before drawing with Leicester last time out to boost their hopes of staying in the division, but he acknowledges that quadruple-chasing Liverpool will provide a far bigger test.
The Toffees boss still believes they can pull off an upset, though, as he added: "If we don't then we may as well not turn up. Can we be realists? Yeah. We're going up against the form team in the world.
"Great individuals, great manager, great process to get to where they've got to. But it's a game of 11 men against 11 men and we absolutely have to believe that if we do our jobs right, we give absolutely everything from the first minute until the last... it will have to be from our point of view pretty faultless to get the result we want, but do we believe?
"Yes, because the Evertonians turning up at Anfield and the ones watching at home, they believe.
"I'm excited to go to Anfield. I understand how tough it is. We'll be everyone's favourite not to get anything from the game in terms of the outside, but I don't mind that.
"My eyes are on what we've got in front of us during the next month, and the Liverpool game comes first. We give everything in that game."