The Brazil international caught the eye with his effervescent displays for Porto, leading Man United to pay €15m (£12.9m) for his services in the summer of 2020.
Telles arrived at Old Trafford to challenge Luke Shaw for the left-back spot, but the 30-year-old struggled to acclimatise to Premier League football and was loaned out to Sevilla last season.
While on the books with Los Palanganas, Telles became a Europa League winner, playing 95 minutes in the final against Roma and contributing three assists from 38 matches in all tournaments.
However, Sevilla did not pursue a permanent deal for the defender, who has allegedly not yet returned to pre-season training with Man United as his camp try to engineer an exit.
The Red Devils are at risk of losing Telles on a free transfer next year, but they can also trigger a one-year extension in his contract until 2025 should they wish to protect his value.
Either way, the ex-Porto man is expected to pack his bags this summer, and according to journalist Jorge Nicola, Flamengo are hoping to bring Telles back to his homeland.
Given Telles's contract situation and status as a peripheral player at Man United, Flamengo are supposedly hopeful of paying less than €7.5m (£6.4m) to sign him in the coming weeks.
However, Flamengo's interest is apparently at its earliest stages, and it is unclear how much Man United would hold out for before giving the green light to a sale, but the Red Devils cannot afford to play hardball.
Flamengo currently have Ayrton Lucas and Filipe Luis as their left-back options, but the latter - once of Chelsea and Atletico Madrid - will turn 38 next month and is out of contract in December.
The Brazilian side are also said to be concerned at the prospect of losing Lucas, and head coach Jorge Sampaoli could therefore offer Telles the chance to reignite his career in Serie A.
The 30-year-old has scored one goal and set up eight more in 50 matches for Man United since 2020, but he is now third choice in the pecking order behind Shaw and Tyrell Malacia.
Man United have already sanctioned three defensive departures this summer, allowing Phil Jones, Axel Tuanzebe and David de Gea to walk out of the door upon the expiration of their contracts.
More could follow in the coming weeks, including Telles's fellow left-back Brandon Williams, as well as Eric Bailly, who also did not report for pre-season training on Monday.
In addition, Harry Maguire's future has been plunged into even more doubt after the centre-back announced that he had been stripped of the captaincy by Erik ten Hag.