The 18-year-old enjoyed a breakthrough campaign at the Emirates last season but has found opportunities harder to come by this term, featuring 12 times across all competitions without starting a Premier League match. Increased competition following Arsenal's summer recruitment has limited his pathway, prompting the club to sanction a temporary move abroad.
Nwaneri committed his long-term future to the Gunners by signing a new contract until 2030 and remains firmly part of Arsenal's plans, with no obligation included to make the switch permanent. While an initial stance from both player and club was that staying within a title-challenging squad would best serve his growth, the prospect of consistent minutes in a new league ultimately tipped the balance.
Manager Mikel Arteta admitted the decision was rooted in protecting the youngster's progression rather than allowing his development to stall.
"Talented young players need minutes and Ethan wasn't getting enough," Arteta explained. "The last thing we want is to slow his development because he is such a talent. Sometimes that means leaving a comfortable environment and facing something completely new."
Marseille emerged as the preferred destination after Arsenal reflected on William Saliba's successful loan spell there earlier in his career. The presence of head coach Roberto De Zerbi, renowned for his work with young players and an adventurous style of play, was another decisive factor.
Arteta acknowledged the emotional challenge of the move, but believes the experience will be invaluable. "There is always fear and insecurity when you leave what you know," he said. "But being thrown into an incredible football atmosphere will make him so much better."
Nwaneri, an England Under-21 international, impressed last season with nine goals in 37 appearances, operating mainly from the right wing. With Marseille currently third in Ligue 1 and pushing on multiple fronts, the teenager is expected to gain the regular exposure Arsenal feel is essential at this stage of his career.
Arsenal, meanwhile, continue their Premier League title charge from the summit, while Marseille look to respond domestically after a difficult European outing in midweek.
Aston Villa's season has been dealt a significant blow with confirmation that Boubacar Kamara will not return to action before the summer after undergoing surgery on his left knee.
Manchester United have confirmed that Casemiro will depart Old Trafford at the end of the season, with the club opting not to extend the Brazilian midfielder's contract beyond its current expiry.
Arsenal were left managing another fitness concern in January as Kai Havertz suffered a fresh setback in his recovery from a long-term knee injury.
Matthijs de Ligt will miss Manchester United's trip to London this weekend as the Red Devils prepare to face Arsenal in a crucial Premier League fixture scheduled for Sunday.
