Chelsea had struck a deal with Benfica when the Portuguese club bought the attacking midfielder from Partizan Belgrade last year that they could have first option on a £12m transfer should he be sold.
"It'll be good for him and Benfica," Drulovic told reporters. "Going to a very strong league will help him even more to become a major player worldwide.
"Markovic made an excellent season at Benfica last year, he evolved a lot.
"He's 20 years old and has a long time to play," he continued. "Markovic could prove to become a very important player in Europe."
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