Sam Allardyce wants the 23-year-old on a season-long loan, with a potential £5million move in place next summer should he impress.
The Black Cats manager, who is reportedly being lined up for a move to the vacant England job, is looking for a new right-back, and considering a move for either DeAndre Yedlin, Danny Simpson or Mathieu Debuchy.
But a loan deal for the current PSG defender, who spent last season on loan at Nantes, may be the most cost-effective deal for Sunderland.
Sabaly made 28 league appearances for Nantes in Ligue 1 last season, also scoring twice as the club finished 14th in the league table. However, the side did have the 6th best defensive record in the entire division, conceded just 40 goals in 38 league games.
In comparison, Sunderland were ranked 16th in the Premier League table in goals conceded, as they narrowly avoided relegation.