West Ham United manager David Moyes is set to begin his tenure in charge without his main striker Javier Hernandez after the Mexico international was ruled out of the Premier League trip to Watford this Sunday (19 November).

The 29-year-old suffered a hamstring injury in the 3-3 friendly draw with Belgium last week and was subsequently withdrawn from the squad for the second international against Japan.

Hernandez returned to West Ham for a scan on the blow, and though scans have shown the injury not to be serious it will keep him out of the game at Vicarage Road and potentially Moyes' first home game in charge against Leicester City next Friday, according to the Evening Standard.

The news is a major blow for Moyes, who will now have to decide between Andy Carroll, Diafra Sakho and Andre Ayew to lead the Hammers attack.

Though Hernandez has only netted four times since arriving from Bayer Leverkusen in the summer, he started each of West Ham's 11 Premier League games this term under Slaven Bilic.

He has been deployed across the front-line, including on the left in the goalless draw with West Bromwich Albion in September, but had returned to a berth in the middle in the last four games.

Moyes has pledged to give Hernandez a fair opportunity to impress after regularly overlooking him to lead the attack during his spell as manager of Manchester United.

The one-time Real Madrid forward made just five Premier League starts during the Scot's eight-month tenure, but can expect to be focal point of the West Ham attack upon returning to full fitness.

James Collins, Michail Antonio, Sam Byram, Jose Fonte and Doneil Henry are all expected to miss the game with injuries suffered prior to Moyes' arrival.

Preparations for Moyes' first match in charge have seen him recruit three new additions to his backroom team.

Alan Irvine, who worked with him at Preston North-End, ex-Hammers defender Stuart Pearce and Billy McKinlay – formerly a coach at Real Sociedad and scout at Sunderland under Moyes – have joined as his assistants.

Former Everton and United goalkeeping coach Chris Woods remains at the club, having joined in June 2015.

"I'm really pleased to welcome Alan, Stuart and Billy to the club, along with Chris who was already here, and I'm looking forward to working with them all," Moyes told the club's official website.

"I wanted to get their appointments finalised as quickly as possible and it's great that we now have a full week together before the game at Watford on Sunday.

"I've obviously worked with Alan, Billy and Chris previously, and I'm also looking forward to working with Stuart, who I have got to know well over the years.

"They all bring different qualities, and they all share the same desire and hunger to make a positive contribution here.

"It's all about working hard on the training pitch and getting the results we need as quickly as possible – that's all we are focused on."

Javier Hernandez
Hernandez has returned from international duty with a hamstring injury. Getty Images