During the summer, N'Doye opted to make the move to St Andrew's from Angers, and the 31-year-old has gone on to become a regular in the Championship with 24 appearances being made for the Blues.
However, according to L'Equipe, Birmingham will have to fend off interest from Angers and Strasbourg in order to keep the player in the West Midlands.
N'Doye enjoyed an excellent two years at Angers with 14 goals being scored in 65 league appearances, but the club are currently fighting for survival in Ligue 1.
Strasbourg are in midtable, but they remain just five points clear of the relegation zone and Ndoye is regarded as a potentially-important addition to their first-team squad.
The Senegalese has 18 months remaining on his contract at Birmingham, who are unlikely to be willing to part ways with the player unless they receive a significant offer.