By Chris Harris
The Brazil Under-19 captain impressed on his Reserve team debut in September and will provide midfield back-up to Gilberto and Cesc Fabregas on Tuesday night.
"He's a little bit in between Tomas Rosicky and Gilberto," said Wenger. "He's more a defensive midfielder, maybe he's not the final ball giver like Cesc Fabregas but he's a good link player. I saw him when I was watching another player in Brazil [Ramon].
"He is a little bit unsettled at the moment, he is still in a hotel and is living in a different country for the first time."
Gael Clichy has also been named in Arsenal's 18-man squad after making his first-team comeback as a substitute against Watford on Saturday. However, the French left back will not start in Moscow.
"Gael is fit but I don't think I'll start him. I won't change the defence right now," said Wenger.
Robin van Persie