West Ham decided to start actively looking for a replacement for Graham Potter after the 3-0 home defeat against Tottenham two weeks ago.
Nuno Espirito Santo was the No 1 target and was available after being sacked by Nottingham Forest on September 9.
The final straw for Potter was last weekend's 2-1 home defeat by Crystal Palace, although he was already under serious pressure.
Talks with Nuno's agent, Jorge Mendes, stepped up and it was only a matter of time before Potter lost his job.
There was a real fear West Ham would be relegated for the first time in 15 years if the change was not made.
West Ham were willing to wait until next month's international break to make the change but Nuno wanted to start working straight away - despite the fact West Ham have two tough away games, agai