Alfred Finnbogason says Chelsea's strikers will enjoy playing with Hakim Ziyech.
The Ajax midfielder will join Chelsea this summer for a fee rising to €44m.
FC Augsburg striker Finnbogason played with Ziyech at SC Heerenveen and told De Telegraaf: “I already knew he was good, huh. But what he has shown in recent years is not normal.
"That I had a good click with him? Who does not have a good click with Ziyech is not a good striker.
"You just have to move well. He gives the balls exactly how you want them."
The Iceland international added: “Without a doubt, the Premier League will be a big test for him. Players are better and more aggressive, but you see what he has already shown at Ajax with his qualities in the Champions League.
"He is something special and will be a big signing for Chelsea. The pressure will be great, but he can deliver. He is no longer a young boy either, he knows how it works."