Now with just one win in their last six matches, West Ham are struggling to reach the highs of last season's European qualifying campaign.

Slaven Bilic has the opportunity to use the upcoming transfer window to refresh his team and have his side push on in the league. If bad results continue they could be pulled into a demoralising relegation battle.

The Hammers have scored in five of those last six matches but with twelve goals conceded at the other end, they require players to come in and steady the ship.

Their strikers are faltering, too, with only one goal scored between all of them in league action this season.

Those are the priorities for Bilic and if he can buy well, the London side are likely to be well clear of danger and potentially well placed to have an excellent campaign next season.

Here are our FIVE players that should be on Bilic's Christmas wishlist...

Asmir Begovic

Football Soccer Britain - West Ham United v Chelsea - EFL Cup Fourth Round - London Stadium - 26/10/16
Chelsea's Asmir Begovic makes a save
Reuters / Eddie Keogh
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West Ham goalkeeper Adrian has been struggling massively this season and with just Darren Randolph available as a replacement, the position should be a priority for Bilic in this window.

Asmir Begovic is an excellent goalkeeper as evidenced by his time at Stoke City and after numerous appearances for Chelsea last season, he has found himself relegated to EFL Cup action under Antonio Conte.

A January move would be beneficial for both parties and go a long way to putting a cork in Bilic's leaky defence.

Clement Grenier

Football - Olympique Lyonnais v Tottenham Hotspur - UEFA Europa League Second Round Second Leg - Stade de Gerland, Lyon, France - 21/2/13 
Tottenham's Mousa Dembele (R) in action with Lyon's Clement Grenier 
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Clement Grenier is a classy French midfielder who has found himself out of favour at his boyhood club Lyon.

Making just four sub appearances for the French side this season, Grenier has in the past made close to 150 appearances for the club.

A set-piece expert, he'd link up well with fellow countryman Dimitri Payet and offer the Hammers more creativity in the middle of the park.

Often tipped for the top in the past, if the Hammers can capitalise on his situation at Lyon they'd likely be getting a good deal for a player that can impact games and win points for Bilic.

Callum Wilson

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Bournemouth's Callum Wilson celebrates scoring their first goal 
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With West Ham's strikers scoring just one goal between them in the league this season, Bilic badly needs firepower at the tip of the Hammers' attack.

In Callum Wilson, he'd be getting an accomplished finisher and a player with a very bright future ahead of him in the game.

A potential England international, Wilson was vital to Bournemouth's promotion from the Championship two years ago and has scored four goals in eleven appearances this term.

West Ham are a much bigger club than Bournemouth and a move to London would represent a big step in his career, but one he is ready for.

Moussa Dembele

Britain Soccer Football - Celtic v Rangers - Scottish Premiership - Celtic Park - 10/9/16
Celtic's Moussa Dembele scores their second goal 
Reuters / Russell Cheyne
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Everyone's talking about him but nobody knows where he'll end up, if he moves from Celtic at all over the next 12 months.

The in-form Celtic man has scored 17 goals this season including five in Europe and would certainly bring life to West Ham's faltering frontline.

With experience of English football at Fulham, Dembele is well placed for a Premier League move and is unlikely to need much time to settle in.

With him playing in Scotland, a deal for him would represent good value for the club who can attract him, just look at the rise in value of Virgil van Dijk and Victor Wanyama over the last few seasons.

Carlos Bacca

Jun 25, 2016; Glendale, AZ, USA; Colombia forward Carlos Bacca (7) controls the ball against the United States during the third place match of the 2016 Copa America Centenario soccer tournament at University of Phoenix Stadium. Mandatory Credit: Mark J. Rebilas-USA TODAY Sports / Reuters Picture Supplied by Action Images *** Local Caption *** 2016-06-26T023727Z_1540991888_NOCID_RTRMADP_3_SOCCER-2016-COPA-AMERICA-CENTENARIO-COLOMBIA-AT-USA.JPG

Colombian striker Carlos Bacca offers a different sort of striking option compared to the more youthful Callum Wilson and Moussa Dembele.

A proven goalscorer over his entire career, Bacca has scored 217 goals in 423 professional appearances. He has experience of football in two continents and four countries and would be ready to do an immediate job for Bilic's side.

Despite being at Italian giants AC Milan, a move to West Ham and the Premier League could prove tempting for the man who has scored six goals in thirteen games this season.

What's sure is that if Bilic does move for him, he'd be banging in more goals that his current striking options.