The report claims that the Dutch second-tier club want Unal to extend his deal after an impressive second half of the season.
NAC do of course have an agreement with City over the development of youth players.
City announced a five-year partnership with NAC in April which means the Dutch side will get four and six players from the Citizens between the ages of 18 and 21 each season.
City sent the Turkey international out on loan to KRC Genk where he made just two starts. Unal was recalled from Genk in January and was once again sent out on loan to NAC Breda.
The 19-year-old went onto score nine goals and provide two assists in 11 games in the Dutch second tier outfit.
The Turkish international striker joined Genk on a two-year loan but City have the option to call him back after his first season.
Unal is rated as one of the brightest prospects in Turkish football and currently holds the record as being the youngest player to have ever scored in the Super League aged just 16 against Galatasaray in 2013.