According to David Ornstein, club captain Martin Odegaard is not in the squad due to an injury picked up in training last week. This has left a spot open for Nwaneri, who has been incredibly impressive for the U21 team.
If the teenager does get onto the pitch in west London, he will become the first player aged under 16 years old to play in the Premier League. He will also beat Liverpool's Harvey Elliott for the record of the division's youngest ever player.
According to The Metro, Nwaneri was expected to spend the season in the U18 squad, but was quickly promoted to the U21s after turning heads with his performances.
Arteta has reportedly been impressed with the England U17 international, who picked up an assist in his first ever Premier League 2 appearance this week. Nwaneri didn't make the U21 squad to face Wolves on Saturday as he was told he would be joining the first-team squad for the Brentford clash.
The Gunners are looking to bounce back from their first defeat of the season against Manchester United in their most recent game. But news of Nwaneri's inclusion in the squad made many Arsenal supporters feel very old, as many took to Twitter to express their opinions:
William Saliba reveals crucial role Mikel Arteta played in convincing him to stay at Arsenal
The 21-year-old has been one of the leading centre-backs in the top-flight this season after spending three consecutive campaigns on-loan in Ligue 1.
Saliba was full of praise for the Arsenal manager, as the French international told Canal Plus (as per The Mirror):
“We spoke a bit at the beginning of the season. He was happy with what I did whilst on loan. He’s a very good coach, who really knows what he’s doing. He is clear in everything that he says.
"He has helped me integrate quickly into this system of play. Every day he gives advice to be better on the pitch. I came back here [to Arsenal] to impose myself and it’s nice to start well, as I have.
“We have had a very good start to the season until the match at Manchester [United]. We [were] first and we want to continue like that. As everyone knows, I didn’t play. For me, it was better to go away.
"I’m a young player and it’s always better to play and gain experience, make errors and learn. If you don’t play, you can’t progress."