The winger has a knee injury ahead of the second-round tie at the City Ground.
Jamaal Lascelles, Jonjo Shelvey and Javier Manquillo – who sat out the weekend's defeat to Chelsea – are also expected to sit out the game, while Isaac Hayden is suspended.
Asked about injuries, United manager Rafa Benitez said: "Still the team. Matt Ritchie has got a knee injury, which could be another problem."
Benitez will make a number of changes for the game, which is being televised.
"We will give chances to some young players," said Benitez.
On the importance of the cups this season, Benitez added: "We cannot lie to our fans though and pretend this is the most important game of the season.
"We want to win if we can win. We will try, but we will make changes, because we have to. We want to progress, but it has to be this way.
"I hope that the players we put out can win the match."