The Newcastle United striker suffered a deep gash on his leg in last weekend's 1-1 draw against Birmingham City.
Mitrovic was given oxygen as he was stretchered off the pitch at St Andrew's.
However, United manager Benitez, speaking ahead of tomorrow's Championship game against Brentford, is confident that the striker will be back on the field next month.
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“I spoke with him and he is progressing," said Benitez.
"He needs time. Normally they say two or three weeks, and hopefully everything will be fine."
Meanwhile, forward Sammy Ameobi, back from a loan spell at Bolton Wanderers, is in Benitez's squad for the Brentford game.