West Ham manager Sam Allardyce has been given the backing of the struggling Premier League club's owners in the wake of their FA Cup humiliation at the hands of Nottingham Forest.

Allardyce is odds-on to be the next top-flight boss to lose his job but the 59-year-old has been given the support of co-chairmen David Sullivan and David Gold in an open letter published on the Hammers' official website.

The duo also confirmed that they are close to completing their first signing of the January transfer window.

Allardyce is the only manager of a side currently in the bottom five of the Premier League who was in charge at the start of the season and Sunday's 5-0 thrashing by Forest has increased the pressure on the former Blackburn boss.

However, Sullivan and Gold have backed Allardyce to turn things around for the Hammers, who face a Capital One Cup semi-final against Manchester City at the Etihad Stadium on Wednesday.

"Like all West Ham United supporters we feel frustrated and hurt by our recent results. We understand how you feel and we, the board, feel the same," the open letter read.

"It is never enjoyable being knocked out of a cup competition and losing by such a large scoreline to a lower division side is hard to take for us all. We thought the youngsters gave their all and did not stop trying but in the end Nottingham Forest's experience proved too much for us.

"Sam has been handed a near impossible task of coming through three crucial games in the space of six days with a squad of only 14 fit and available senior players. This is not an excuse it is a fact.

"We know Sam has not lost his ambition or desire and is committed to making West Ham United a great Premier League club.

"We now face a Capital One Cup semi-final on Wednesday followed by a vital Barclays Premier League trip to Cardiff on Saturday. Despite an extremely difficult draw, we are determined to do all we can to get to the Capital One Cup final over two legs with Manchester City.

"We hope to have several of our missing players back in time for Cardiff and we go there knowing that a win can get us out of the bottom three. Such is the nature of the Premier League this season; there are only six points between us and the team in 13th place.

"Make no mistake, though; we are under no illusions as to the seriousness of our current predicament in the Premier League. But on the board we have a combined talent of running football clubs and we will draw on all of our nous to get West Ham United out of this situation.

"We have experienced difficult times before and we know what will get us results - hard work, determination and perseverance.

"To that end, we are all working round the clock to do everything in our powers to help arrest our slump in form."

It is the seemingly ever-growing injury list at West Ham that has been highlighted as the main reason for the club's poor run, which has seen them fail to win a league game since November 30.

Andy Carroll has yet to feature this season while James Tomkins, Winston Reid, James Collins, Mark Noble and Ricardo Vaz Te are also injured and captain Kevin Nolan is currently banned.

"Our first priority is to get our key players fit," the letter continued.

"Our record signing Andy Carroll continues to make good progress following his return to first-team training and he should be back on the pitch very soon... Trust us, Andy Carroll is desperate to play and is ready to do his bit for the team and we are confident that the return of all of our injured players will lead to an upturn in our fortunes.

"Thereafter, our second priority is to bring in the new talent needed to bolster our squad in the most needed areas.

"January is not an easy time to do business but we are pleased to confirm we are close to securing one of our key striking targets. A defender is high on the list of priorities as well and progress is being made on that front."