The 24-year-old, who is a product of Arsenal’s youth system, is an experienced Premier League player, having made 132 first team appearances for the Gunners. The Englishman was initially deployed as a right back but has since expressed his desire to play as a central midfielder, something he has done on multiple occasions this campaign under Mikel Arteta.
Mourinho is not a coach who is wedded to a particular formation; this season he has set up Roma in both a 4-2-3-1 and a 3-5-2, giving him tactical flexibility for particular opponents. This also allows him to utilise Maitland-Niles in a variety of roles.
Should the Portuguese coach continuing using the 3-5-2 formation, Maitland-Niles is likely to be deployed in the centre of the midfield five, allowing him to move Henrikh Mkhitaryan into a more attacking role. He could also play on the right side of the midfield five, combining his qualities as both a midfielder and a right back.
If Mourinho returns to using a 4-2-3-1 system then it’s likely that Maitland-Niles would be used as part of the midfield two in front of the defence; the Englishman shines with the ball at his feet, being a good dribbler, and he is also strong at applying pressure and clearing the ball. This formation would also allow the Portuguese coach to play him as a right back if needed.