Having been under a transfer ban last season, the Blues are now flexing their financial muscle in the transfer market. So far, they have spent £136m on Werner, Hakim Ziyech, Ben Chilwell, and Malang Sarr, with Kai Havertz on Leverkusen likely to follow.
Werner, who scored in Germany's Nations League draw against Spain on Thursday, is expected to spearhead the new-look attack.
However, Hasselbaink has asked for patience, and used Pierre-Emerick Aubameyang's settling in period at Arsenal as an example of a player taking time to adapt only to enjoy success after,
"German football is totally different to the English game so it will be difficult for Werner to settle straight in," the Dutchman told Gentingbet.
"We know he's a talented player. We know what he can do. And Chelsea need a player that can score goals.
"But, we also need to give him the time. If you look at [Pierre-Emerick] Aubameyang when he came, he needed six months. So, give him those six months as well."
As for Ziyech, Hasselbaink is excited to see him in a Blues shirt.
"Hakim Ziyech is very creative, has an excellent left foot, is very good at set pieces and I expect a lot of assists from him," he said.
"He’s got that aura around him in that he wants the ball. He wants that responsibility, he’s not afraid to score goals.
"Physically, he’ll possibly have a problem in the beginning, so he has to be smarter with his physical ability. But he is a silky, beautiful player and something that Chelsea don’t have – a midfielder with a left foot who can bring something different."
Werner contributed to 36 goals in the Bundesliga last season via 28 scored himself complemented by eight assists.