West Ham United striker Javier Hernandez has handed a sizable boost to new manager David Moyes by insisting that he remains committed to the struggling Premier League club and branding claims that he has asked to leave in January as "completely false".

Former Manchester United super sub 'Chicharito' returned to English football in a £16m ($21.1m) deal in July after a prolific three-year Bundesliga stint with Bayer Leverkusen, headlining a seemingly impressive transfer haul that included another trio with plenty of top-flight experience in Joe Hart, Pablo Zabaleta and record signing Marko Arnautovic.

However, West Ham have floundered during his first few months in east London, with the embattled manager responsible for bringing Hernandez back to the Premier League - Slaven Bilic - finally relieved of his duties after a dire run of just two wins from their opening 11 matches left his underperforming side in the relegation zone.

Although Hernandez is responsible for four of the Hammers' 11 league goals so far this term, doubts regarding his future have already begun to circulate after David Moyes was chosen as the successor to Bilic on an initial six-month contract.

The pair previously worked together during a wretched 10-month spell at Old Trafford in 2013-14 following Sir Alex Ferguson's retirement, when Hernandez made a total of just eight starts across four competitions.

Such an appointment has prompted speculation that Hernandez is seeking a New Year return to his native Mexico with first club Chivas, although the 29-year-old claims that is simply not the case.

"Completely false," he wrote on Twitter on Thursday (16 November). "I am 100 per cent committed to helping improve the situation we are all experiencing at West Ham. And as I always say, I am #chivadecorazon but I have not asked to leave West Ham at any time."

Moyes will be without Hernandez for the start of his West Ham tenure due to a hamstring injury sustained by the forward while on international duty with Mexico during the 3-3 friendly draw with Belgium in Brussels last week.

He missed the subsequent win over Poland in Gdansk after returning to his club for a scan and will remain sidelined for the new manager's first game in charge against Watford at Vicarage Road on Sunday. He is also expected to be absent for the Friday night visit of Leicester City to London Stadium and the subsequent trip to Everton at the end of the month.

Addressing his reunion with Hernandez last week, Moyes warned the player would not receive any "special treatment" but backed him to retain his starting berth as long as he keeps scoring and demonstrates a strong work ethic.

"If he is scoring goals and working hard, he will be in," he said. "It will be the same for the rest of the team.

"He's a top goalscorer, a brilliant finisher. It was difficult for him at United because I had Robin van Persie, Wayne Rooney, Danny Welbeck, Shinji Kagawa, so there was lots of competition."

Javier Hernandez
Javier Hernandez has scored four goals in his first 11 Premier League outings for West Ham BEN STANSALL/AFP/Getty Images