Indeed, Wissa has been expecting the Bees to agree his move to Tyneside this week after the west London side completed the signing of Dango Ouattara from Bournemouth.
However, according to sources, Brentford are still hesitating in allowing Wissa to leave amid suggestions they now value him above their original £40m asking price.
Reports suggest Brentford now value Wissa, who did not feature for the club during pre-season, at £60m.
As a result, the ongoing conflict between Wissa and Brentford has escalated, with the forward removing all photographs of him playing or training for the club from his official Instagram page.
Tottenham are also interested, but as things stand Newcastle’s move is more advanced. It now remains to be seen whether Brentford sanction his sale before the transfer deadline.
Wissa has scored 49 goals in 149 appearances for the Bees.