Since making the £16m move from Bayer Leverkusen, the 29-year-old has scored four Premier League goals despite the Hammers' struggles at the start of this campaign.
Earlier this week, reports from Spain emerged which suggested that Hernandez had asked to leave the London Stadium during the January transfer window, with Mexican side Chivas his preferred destination.
However, the Mexican striker took to his Twitter account to refute those suggestions.
He said: "Completely false. I am 100 per cent committed to helping improve the situation we are experiencing all at West Ham.
"And as always I say this I am #chivadecorazón but I have not asked to leave West Ham in no time."
Hernandez worked under Moyes during the Scottish coach's unsuccessful 10-month spell in charge at Manchester United, but he started just five Premier League matches in that time.
Earlier in the week, Moyes warned his striker that he wouldn't be getting any special treatment at West Ham just because he's the club's top scorer this season.