Liverpool already have a very strong starting XI but Tuesday’s shock 2-0 defeat at the hands of Red Star Belgrade in the Champions League suggests the Reds’ squad could do with improving.
The likes of Adam Lallana, Joel Matip and Daniel Sturridge all started in Belgrade and were heavily criticised by fans on social media following their disappointing displays.
If Liverpool are serious about challenging for the Premier League or Champions League titles then they need reliable players to step in and perform whenever called upon.
Jurgen Klopp may decide to dip into the transfer market in January to give his team the best possible chance of finishing the season with a trophy.
Look at what the £75 million purchase of Virgil van Dijk did for Liverpool last winter. It transformed the team and made them so much better defensively. One of two signings can make a huge difference, if the players signed tick all the relevant boxes.
Liverpool have made 10 winter signings since 2007 - but have they all been as successful as Van Dijk? Let’s take a closer look…
Liverpool fans could be forgiven if they’ve totally forgotten about Astrit Ajdarević, a one-cap wonder for Albania who played in midfield.
Signed from Swedish side Falkenbergs for £750,000 in January 2007, Ajdarević played for Liverpool’s youth side but failed to force his way into the first team and was sold to Leicester City in 2009.
Now 28, Ajdarević has since played for a host of clubs including Standard Liege, Charlton and Orebro SK. He currently plies his trade with AEK Athens.
"He is aggressive, quick, is good in the air and I think he's a very good player for the future and also for the present. He is very competitive, but his mentality for me is very good.”
That’s how Rafael Benitez described Martin Skrtel after signing the Slovakian centre-back in a £6.5 million deal from Zenit Saint Petersburg in January 2008 - and how right he was.
Skrtel spent eight years at Anfield before leaving the Reds for Fenerbahçe in 2016. The 33-year-old is still with the Turkish giants now.
West Ham may not have realised Javier Mascherano was an extraordinary midfielder, but Benitez certainly did - hence why he brought him to Anfield on loan in the winter of 2007.
The tenacious Argentina international finally signed a permanent four-year contract with the Reds in 2008 after Liverpool secured his services from the controversial Media Sports Investments consortium, who also owned Carlos Tevez at the time.
Mascherano went on to sign for Barcelona, where he spent seven-and-a-half happy seasons, before moving to Hebei China Fortune earlier this year.
The signing of Maxi Rodriguez from Atletico Madrid on a free transfer felt like a real coup for Liverpool in January 2010 - and the hard-working Argentina international endeared himself to the Anfield faithful over the next two-and-a-half seasons with his work ethic and professional attitude.
Rodriguez didn’t exactly set English football alight but he still managed to score 15 goals in 57 Premier League appearances for the Reds.
He then returned to Newell’s Old Boys in 2012 before signing for Uruguayan heavyweights Penarol five years later. The South American, who turns 38 in January, is still plying his trade Estadio Campeón del Siglo.
With Fernando Torres desperate to leave Liverpool for Chelsea, Kenny Dalglish and the Reds’ hierarchy had very little time to sign a replacement.
They settled on the talented Andy Carroll - although the £35 million transfer fee they paid Newcastle United on deadline day stunned English football at the time.
Unfortunately, Carroll struggled badly at Anfield, scoring just 11 goals in 58 games for the Merseyside outfit.
He eventually joined West Ham permanently in 2013 but his spell with the Hammers has been plagued by injuries. The 29-year-old, once touted as the new Alan Shearer, has scored 33 goals in 128 games for West Ham.
Because of the Andy Carroll-Fernando Torres deadline-day saga, Luis Suarez’s signing sort of went under the radar.
Purchased from Ajax in a deal worth £22.8 million, Suarez would go on to become one of Liverpool’s greatest ever forwards, scoring 82 goals in 133 games over the next three-and-a-half seasons.
Liverpool tried their best to keep Suarez at Anfield but were powerless to prevent him leaving the club when Barcelona came calling in the summer of 2014.
The Uruguayan striker has scored a magnificent 161 goals in 214 appearances for the Catalan giants and remains one of the club’s key players.
To say Daniel Sturridge hit the ground running after joining Liverpool from Chelsea in January 2013 would be an understatement.
The English forward netted 11 goals in 16 appearances during his first half-season at Anfield and followed that up by scoring 24 goals in 33 games during his first full campaign with the Reds.
His performances during the 2013-14 season cemented his status as one of the Premier League’s most lethal forwards, but injuries have sadly hindered his progress since then.
Sturridge is still with Liverpool - although he did have a spell on loan at West Brom last season - but is very much a back-up option behind the likes of Roberto Firmino, Sadio Mane and Mohamed Salah.
Liverpool’s £8.5 million purchase of Philippe Coutinho from Inter Milan is arguably one of the best value-for-money signings of the Premier League era.
Five years later - after scoring 54 goals in 201 games for the Reds - the Brazilian playmaker would become the second most expensive footballer of all time.
Barcelona forked out an eye-watering £142 million for Coutinho’s services in January 2018, much to the disappointment of Liverpool fans, and now he finds himself playing alongside the likes of Lionel Messi, Sergio Busquets and Gerard Pique at the Camp Nou.
After signing for Liverpool in January 2016, Marko Grujic told reporters: “I would choose Liverpool over Real Madrid and Barcelona.”
Fast-forward almost three years and you have to wonder whether the Serbia international now thinks differently.
Grujic, who is now 22, has only made a handful of appearances for Liverpool over the past few seasons.
He spent time with Cardiff City in the Championship last season and is currently on loan at Hertha BSC in the Bundesliga.
Virgil van Dijk
Eyebrows were raised when Liverpool spent £75 million on Southampton’s Van Dijk, but what a signing he’s been.
Many football fans believe the Dutchman is currently the world’s best centre-back and it’s hard to disagree.
Another game-changing signing like Van Dijk in January and Liverpool could finally end their long wait for the Premier League title.