Chelsea manager Frank Lampard has said Christian Pulisic has a lot more to offer the Premier League yet.
Pulisic, who was voted U.S. Soccer's Male Athlete of the Year for 2019 to become the youngest two-time winner of the award, struggled to adapt to life at Chelsea at first but since a hat trick against Burnley in October he has gone on to become a key player for his side.
"There's a lot more to come," Lampard said. "He gets himself in so many great positions with his talent and his dribbling ability so more goals will be the next stage of that.
"I'm really pleased with him because we've asked a lot of him. He's played a lot of games recently, back-to-back in a new league that's very physical but of course we want a lot more as well."
To date Pulisic has scored six goals and assisted five more for Chelsea.
"I don't know how clever it is [having a £40 million buy-back clause for Ake]," Lampard said. "It is what it is. Nathan came through here and when he came to Bournemouth he has done fantastically well. He is a Premier League player. The defence we have here I am very happy with.
"We want a top calibre of player who can improve us. I won't hone in on those three. I said I am happy with the squad, but we have to improve if we can."