The 22-year-old got his marching order three minutes after the restart for a late challenge on Ivan Perisic, with referee Paolo Silvio Mazzoleni needing to consult with the Video Assistant Referee.
Andrea Ranocchia, Rafinha, Mauro Icardi and Borja Valero efforts handed the visitors the maximum points in the tie.
The midfielder's expulsion against the Nerazzuri makes it his third in his career. He saw his first red card when he represented France during the UEFA Under 17 championship in 2012 against Italy and the second came in 2016 while playing for Bastia in a French Ligue 1 outing versus Montpellier.
The former Fulham man has been a consistent figure for the Dacia Arena outfit this season, featuring in 26 league games and scoring twice.
Udinese are now winless in their last 14 top-flight games which have seen them drop to the 17th spot with one place and one point above the relegation zone.