Jeremiah had no clue or whatsoever about the coming of Nazar to his city, in his mind he was done with Nazar from the day he told me to go to Italy and meet a lady called Olivia, who knew secrets about the first species of vampires. He never met him again even when he visited Warlington to murder Stuart, and even when he was in Toronto to kidnap Alice - to him Nazar was just a lost cause. His focus was to save Ben and have him take the cure, that will mean Matthew will die and so will Nazar, finally he could get rid of him.