Brazil international Telles joined United from Porto in 2020 and, although he featured in only nine Premier League games during his first season, the competition he represented was initially seen as a contributing factor in Luke Shaw's improved form.
Shaw enjoyed arguably the best season of his career in the 2020-21 campaign and also impressed at the delayed Euro 2020 as England reached the final, during which the left-back scored.
The Southampton youth product's form dipped significantly for an underwhelming United last season, however, and as such Telles appeared more regularly, making 18 starts from 21 Premier League outings.
Despite the increased exposure to first-team football, Telles rarely looked entirely convincing, particularly on the defensive side of the game.
His days appeared to be numbered when United confirmed young Dutch left-back Tyrell Malacia as new manager Erik ten Hag's first new signing in early July, and Telles' subsequent pre-season performances in several roles have been unspectacular.
Sevilla had been on the hunt for a second left-back since letting Ludwig Augustinsson move to Aston Villa on loan with an option to buy after a solitary unremarkable campaign at the Ramon Sanchez-Pizjuan.
Telles will be expected to play back-up to Argentina left-back Marcos Acuna, who has marked himself out as a key player at the club after an impressive two seasons in Andalusia.
Sevilla, who will play in the Champions League this season, does not have an option to buy the 29-year-old.