Chelsea paid £58m for the 20-year-old United States winger, who will be loaned back to Dortmund for the rest of this season. The German club won't have to pay Chelsea for the loan.
The fee is easily the biggest paid for an American player, surpassing the reported £18m spent by German team Wolfsburg for John Brooks in 2017.
However Sarri said that he did not know the signature was about to be announced – although he was consulted over the move around a month before it was completed.
“I didn’t know anything about [signing] Pulisic yesterday,” Sarri told the BBC following Chelsea's 0-0 draw with Southampton on Wednesday.
“They asked my opinion about him one month ago. My opinion was positive and today I knew that the deal is done but I didn’t know anything.”
Sarri added that he has little control over Chelsea’s transfer activity.
“I am not in charge of the market so I have to tend to my matches and play every three days. I can only say my opinion to the club,” Sarri said.
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