The 22-year-old has enjoyed a successful season with Die Adler, helping his side to the Europa League trophy with victory over Rangers on penalties on Wednesday.
Ndicka moved to the Bundesliga side for around £5m from Auxerre back in 2018, and has gone on to make 139 appearances for the club, including 44 this season.
However, the Frenchman could be set for a move to the Premier League in the upcoming transfer window, with French journalist Hawkins reporting that United have been monitoring the defender.
Ndicka has just 12 months left on his current deal with Frankfurt, meaning he could leave the club for a cut-price fee this summer, or on a free transfer at the end of the 2022-23 campaign. body check tags ::