Ansu Fati and Simon Adingra contributed with a goal and an assist each to help a clinical Seagulls side claim all three points and boost their hopes of progressing to the knockout rounds.
However, the victory in Amsterdam was somewhat marred by the loss of three senior figures, with Milner the first to make way after just eight minutes after sustaining a knock.
Dunk was then taken off at half time after receiving treatment on a groin problem in the closing stages of the first half, while Estupinan – returning from a five-week muscle injury layoff – lasted just 12 minutes after being brought on as a second-half substitute.
Discussing the injured trio in an interview with TNT Sports after the game, De Zerbi said: «I'm very worried about the injuries but it's a problem we are finding in this moment.
»We have a lot of injuries, especially in the full-back position. We have to find another solution, because we play Sunday another crucial game [against Sheffield United] for us and we want to win."
De Zerbi was specifically asked about whether Dunk will be available for selection against the Blades, and the Italian is hopeful that the Brighton captain has not sustained a serious injury.
«I don't know [about Dunk] at the moment,» De Zerbi added. «I think it's not a big problem, but he's played so many games in a row. We have to understand better the [injury].»
Dunk, Milner and Estupinan are the latest names to join a crowed Brighton treatment room that also includes Solly March, Dann
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