Captain Mark Noble has urged West Ham supporters to "get behind" new manager David Moyes, adding he is the "best person for the job".
In an open letter to fans, midfielder Noble, 32, said Moyes was "really liked and respected" by Hammers players who had worked with him during his first spell in charge at the club.
Noble added that he often blames himself for the club's misfortunes.
Moyes, 56, replaced the sacked Manuel Pellegrini on Sunday.
In his previous spell in charge, from November 2017-May 2018, the Scot recorded nine wins and 10 draws from 31 games and led the club to Premier League safety.
West Ham are 17th in the Premier League and Moyes will be in the dugout for their New Year's Day home game against Bournemouth (17:30 GMT).
Noble's letter in full
As captain of this great football club, I want to speak directly to you, my fellow West Ham United supporters.
I know that we were going through a difficult time and the club decided to make a decision to change manager.
David Moyes knows the club and he knows a lot of the players and the players he worked with - myself, Manu, Angelo, Arthur, Cress, Dec, Reidy, Michail and Zaba - really liked and respected him and the way he worked when he was here. He got players playing to their full potential and I hope and believe he can do it again.
I know the fans are not happy with the situation we find ourselves in, but we all love and support our club and we need to get behind the manager and try to get ourselves out of this position.
The manager worked for a long time at a club that is very similar to West Ham in Everton, and you don't stay at a club for that long under the scrutiny of passionate fans unless you are good at your job.
I think David is the best person for the job.
My main thing is that I have always put the club before myself in my career. I just want us to do well. The last few seasons have been full of ups and downs, and I just want the club to be stable.
We hoped that would happen with Manuel because he is such a great guy and had a proven managerial pedigree, but we now need to get back to what we are as West Ham United and achieve realistic targets before aiming higher. When Manuel was appointed, I was really hoping it would be that way, but it didn't work out.
I enjoyed some fantastic football under him and learned so much from him and his staff and I know they were genuinely gutted that it didn't work out, but I do feel like we need to walk before we can run and build something.
We need to win football matches and, however that comes at the minute, I'll take that.
Everybody knows I care for this football club and I want to win so badly, not just for myself but for every West Ham United fan out there.
Sometimes I take so much pressure on my own shoulders that every time we make a mistake or concede a goal, I blame myself, rightly or wrongly, and my emotion can come out.
That's why I have played at this level for so long, because I care so much, and I want us to do well.
I know it's a tough time for the fans, I understand that, but I do believe we need to come together and show the manager support and start getting results because, at the end of the day, results are all that matters.
Let's hope we all enjoy a happy New Year.
Come on you Irons!