Hakim Ziyech is the first signing of Chelsea after the sanction imposed by FIFA of not being able to incorporate players in two transfer windows, which was later reduced to only one period.
The Moroccan attacking midfielder is the first signing since they acquired the services of Christian Pulisic over a year ago.
The 'Blues' have resisted by promoting players from the lower categories of the club, such as Tammy Abraham and Mason Mount, who were on loan in the English Second division, Fiyako Tomori and Reece James.
The young players that Frank Lampard has trusted have performed well, which caused Chelsea not to resort to the transfer market in the last January window.
However, it has been now, once the transfer period has closed, when the Stamford Bridge club has spent more than 40 million to bring in Ziyech, a player who already dazzled in the Champions League against Chelsea.
The Dutch were not willing to part with one of their stars in the middle of the season and have reached an agreement to keep the Moroccan until the end of the season.
It will be then when Ziyech, 26 years old, joins the London team to complete the attack of a Lampard who finally has his first signing.