Manager Frank Lampard believes Hakim Ziyech has added a new dimension to Chelsea's attack after the Moroccan international's masterful performance in Saturday's 4-1 Premier League win against Sheffield United.
Ziyech, who joined Chelsea from Ajax Amsterdam in the close-season for a reported 40 million euros ($48 million), was a constant threat to the United defence as he helped Lampard's side move into third in the Premier League.
The 27-year-old winger has scored twice and provided three assists in seven games in all competitions, and Lampard said he was impressed by how quickly Ziyech has settled.
"He's a top-class player," Lampard said. "He's had a long time out since the Dutch league finished and then he had an injury, so to hit ground running the way he has is a huge plus for us.
"He has given us an extra edge and a different threat. He has an ability to find the last pass or cross, make assists and break teams that have a low block down. He sees the pass and has no fear to try it.
"He exudes confidences in how much he wants to receive the ball and be the important player. He also has great work ethic so he is a complete player. He's been a big plus and I expect there is a lot more to come from him."
Goals by Tammy Abraham, Ben Chilwell, Thiago Silva and Timo Werner helped Chelsea overwhelm bottom side United, but Lampard has warned his players to guard against complacency.
"It was our best performance of the season. We are in a good place, but the level set by Manchester City and Liverpool in the last few years means we have to be in that place every game," he added.