Chelsea announced an agreement with the Germany international last month after reports linking him with Liverpool.
Werner is the second attacking signing of the summer at Stamford Bridge, following Hakim Ziyech’s arrival from Ajax.
The pair will add another exciting dimension to an attack which Pulisic – who struggled for form earlier in the season – has improved with his recent impressive performances.
Speaking to Chelsea’s official website, Pulisic explained how he is excited to see Werner get stuck in under Frank Lampard.
“He’s a very dangerous player,” the American said. “I think he has some similar qualities to me and some of the attacking guys we have. He’s obviously very quick and very good in front of goal.
“He seems like a very humble guy. He wants to come in and wants to work.
“Playing against him has been a great experience and it’s going to be nice to have him on my team as well. So I’m definitely looking forward to that.”
Ziyech and Werner mean Olivier Giroud Tammy Abraham and Callum Hudson-Odoi face further competition for places.