David Moyes said he will always remember his time at Everton fondly but insists he will do everything to ensure West Ham come out on top when the sides meet at Goodison Park on New Year's Day.
The Hammers boss was in charge at Everton for 11 years and three months, guiding them to a fourth-placed finish in the Premier League in 2005 and the 2009 FA Cup final.
And the Scot admitted he still feels something when he returns to Goodison Park.
"Well, I do because I think to manage any club for 11-and-a-half years, I mean I don't know how often it will happen going forward in the future that managers will get the chance to do 11-and-a-half years at one club.
"But, you know, my club is now West Ham. I'm going to Goodison to win for West Ham now, that's my job. I'll do everything I possibly can to do it.
"But they'll never take away my memories, and probably the biggest is the players I had through my time there. Great players, great to work with, really good characters, and I enjoyed my time very much."
Moyes has passed the one-year mark during his second spell in charge at the London Stadium and, after being brought in to avoid relegation last season, West Ham currently sit 10th in the Premier League table.
Everton will be without fans after Liverpool was moved from tier two to tier three of the government's coronavirus restrictions from Thursday, but the Hammers boss still expects a difficult game.
"It's a really tough game at Goodison, it always has been. Over the years, Goodison has never been an easy place for any team to go and win.
"I really enjoyed having that behind me when I was there. They've got an exciting team, they've spent an awful lot of money in recent years, the owners have certainly backed the managers and given them the opportunity to bring in the players they want.
"So that's why I think Everton will now try to compete at the top end, so it'll be a really tough game for us."
