With Liverpool launching what looks like their most promising title challenge since the 2013/14 season, it's becoming increasingly clear that Jurgen Klopp wants to strengthen his squad.

One position where the Anfield boss needs back-up is in the wide attacking area. While Liverpool have some serious talent available, there is not much depth on the flanks.

Adam Lallana is flourishing in a deeper role this season, Roberto Firmino has become the focal point of Klopp's pressing game in a central position and James Milner is almost out of the picture now, spending the majority of games at left-back. Daniel Sturridge could be an option, but he has been openly hostile to playing out wide in the past.

Speaking in November, Klopp acknowledged that with Mane away at the African Cup of Nations and Danny Ings and Coutinho facing long spells on the sidelines, he would have no choice but to make signings.

"Three strikers is enough, I think. But when Sadio is away we will be without a winger. We do not have many wingers, I would say," Klopp explained.

"Roberto Firmino could play as a kind of a winger, which would then just give us two strikers [Origi and Sturridge]. That’s how it is.”

Judging by the flood of transfer rumours surrounding the club this month, it's clear that Klopp sees the wide position, rather than the central one, as his priority.

So who are the men being linked with a move to Anfield?

​Emil Forsberg, RB Leipzig

(Bongarts/Getty Images (Bongarts/Getty Images)

The 25-year-old Swedish international tops the Bundesliga's assists table this season for dark horses RB Leipzig.

Liverpool had been linked with a £20m deal for him after their approaches for Dortmund youngster Christian Pulisic were rebuffed.

While Forsberg's agent has been talking up a move this week, Leipzig's manager Ralph Hasenhuttl has said he is not for sale "under any circumstances".

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Jese Rodriguez, PSG

(Getty Images) (2016 Getty Images)

At 23 years old the Spanish forward already has an impressive trophy cabinet. After coming through the Real Madrid academy, he went on to win La Liga, the Copa del Rey and the Champions League twice.

Despite never really holding down a first-team place at the Bernabeu, Jese secured a £21m switch to PSG in the summer.

Unfortunately, it hasn't really worked out for him in France - having been limited to just two starts - and boss Unai Emery has said the chance of him leaving in January "is a possibility".

Julian Brandt, Bayer Leverkusen

(Getty) (Getty Images)

The predominantly left-sided 20-year-old has impressed for Bayer Leverkusen over the past two seasons, notching up six assists in the Bundesliga this term.

Signed from Wolfsburg's youth academy, Brandt was part of the Germany team that won the under-19 World Cup in 2014, before going on to represent the senior side. He notched seven assists as Germany won silver at the Rio Olympics last year.

With Leverkusen down in mid-table, the youngster could be tempted away. It is reported he has a release clause of around £17m which would be an absolute snip.

Alex Oxlade-Chamberlain, Arsenal

Alex Oxlade-Chamberlain is a January transfer target for Manchester City (Getty)

At something of a crossroads in his career, Oxlade-Chamberlain has been unable to secure a first-team place at the Emirates and has been linked with a move to Liverpool and Manchester City.

Speaking in October, the 23-year-old admitted he could be open to an exit in order to get more playing time.

"“There is going to come a time in my career, and I think I'm approaching that, when I do need to be getting more regular football," he told Sky Sports' Goals on Sunday.

Gabriel Barbosa, Inter

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Gabriel Barbosa has struggled at Inter since making a £25m switch from Brazilian side Santos last year.

After the forward managed just 20 minutes of Serie A action in the first half of the season, manager Stefano Pioli admitted he could be shown the exit door - even just on loan.

Any hopes for a move were dampened this week, however, with his agent telling AS that the 20-year-old will stay in Italy.

Quincy Promes, Spartak Moscow

(Getty Images)

Speculation around the Dutchman's future gathered pace this week when compatriot Giorginio Wijnaldum urged him to join Liverpool.

The 24-year-old has played 72 league games for Spartak since joining in the summer of 2014, scoring 37 goals and making 17 assists.