The forward has not scored for West Ham since October.
Antonio has been involved in 10 goals in his last 10 Premier League London derbies, but has not found the net for the Hammers since October 24 during a 1-0 win over Tottenham.
The 31-year-old started the season in emphatic fashion, scoring four goals in the first three top-flight matches, but has only scored three more times since.
“I think when you’re a centre forward we can think of many who go through a barren spell and don’t quite get the goals and it’s not going in for them,” Moyes said.
“I mean, Mic been a little bit unlucky, he had a really good header the other night that the keeper made a save from. Mic is really important for us, he is a focal point for our team.
“We’ve needed him over the last couple of years playing as a centre forward. We’ve missed him when we have not had him so I’m hoping we can get him back into scoring ways and into top form.”
The Hammers currently sit fourth in the Premier League, a point ahead of Arsenal in fifth and three points clear of Manchester United.
Having been facing relegation when Moyes took over in December 2019, West Ham have already booked their place in the last 16 of this season’s Europa League and are targeting the top tier of European football.
“We are playing the Champions League winners,” the Hammers boss said.
“Last week we played the Champions League finalists as well. I said a few weeks ago, I really want us to play the best teams and see how we do and see where we are at, it is the only way to find out.
“I said at the start, can we challenge them? How well can we do against them? So we’ll try and do that against Chelsea.”
Moyes is likely to still be without Aaron Cresswell for the match against Chelsea while Angelo Ogbonna remains sidelined with a cruciate ligament injury.