Ayoub has made over 130 appearances for Utrecht and scored 15 goals since breaking into the first-team.
The 23-year-old was a member of the famed Ajax youth academy before joining Utrecht in 2009.
After progressing through the ranks in the Utrecht youth sides he broke into the first-team in 2012 and has established himself as a key member of the side.
Ayoub, who can play in central midfield or on the left side of midfield, is entering the final year of his contract at Utrecht and the club would prefer to cash-in on him now rather risk allowing him to run down his contract and leave for nothing next summer.
Yassine Ayoub of Utrecht
Scouts from teams across Europe have been keeping tabs on the former Holland Under-21 international for some time and Leicester and Sunderland are among the clubs to monitor his progress.
Sunderland boss Simon Grayson is keen to bolster his squad before the close of the transfer window with the Black Cats manager short of quality in his ranks.
Leicester are also weighing up a move for Ayoub to strengthen their midfield options with Riyad Mahrez and Demarai Gray both linked with moves away from the King Power Stadium this summer.