Slaven Bilic expected his sacking by West Ham after a poor start to a "crucial season" which club bosses believe can still lead to a top-10 finish in the Premier League.
Bilic, who was appointed in June 2015 on a three-year contract, was axed on Monday after Saturday's 4-1 loss to Liverpool left West Ham 18th in the table after 11 games.
Former Everton, Manchester United and Sunderland boss David Moyes is anticipated to be named as his successor - to become just the Hammers' 16th boss in 117 years. Moyes on Sunday expressed interest in replacing Bilic.
After finishing seventh in his first season and 11th last term, Bilic paid the price for a poor start to his third season as boss.
"I suspected it to be fair," Bilic told Sky Sports News as he left West Ham's training ground.
"We didn't start this crucial season well. We hoped that we could make that step (up) from the start and thought we could make it.
"Of course, you are always hoping and believing in yourself that you can turn it around and do it, otherwise you wouldn't be in this level.
"But it doesn't mean I don't understand the move that the club has made.
"No hard feelings. When I look back on my time, I am very proud of my work here."
The West Ham hierarchy "believe a change is now necessary in order for the club to move forward positively and in line with their ambition", the statement which announced Bilic's departure said.
In a further statement, posted on whufc.com, co-chairmen David Gold and David Sullivan suggested the level of summer recruitment of the likes of Marko Arnautovic and Javier Hernandez had not been matched by on-field performances and results.
A "quality manager" is expected to "inject fresh ideas, organisation and enthusiasm into a very talented squad".
The pair said: "During the summer, the board invested heavily signing the players Slaven believed would complete the squad he needed to push the club back towards the level we had reached in his first season, and we believe we have the players capable of doing that.
"We have not seen enough indication of the required improvement to give us the encouragement that things would change and we would meet our Premier League aspirations this season.
"We believe a change is now necessary to ensure we can begin to move the team back in the right direction."
Gold and Sullivan said the decision to sack Bilic had been made with "heavy hearts".
They praised the Croatian for his role in the move from Upton Park to the former Olympic Stadium, particularly the concluding win over Manchester United in the final home game of 2015-16 which helped to secure European qualification.
West Ham finished 11th last season, in their first in Stratford, but have just nine points and two wins so far this season.
Bilic's assistants Nikola Jurcevic, Edin Terzic, Julian Dicks and Miljenko Rak have also left the club with immediate effect.
Goalkeeping coach Chris Woods, who worked with Moyes at Everton and Manchester United, is the only member of the coaching staff who still appears under 'staff' on the club website.
Moyes on Sunday told beIN SPORTS: "I've had no contact from West Ham but I've always said I want to go back into club management. If the right opportunity comes around, I'd be interested."