Liverpool’s FA Cup campaign is in doubt after being forced to a replay by League Two side Plymouth Argyle. Their 0-0 stalemate means that they are forced to a replay against The Green Army at Home Park next Wednesday.

Manager Jurgen Klopp made 10 changes to his side and it clearly back fired. The winner of the replay will face Wolverhampton Wanderers at home in the fourth round.

Klopp’s side are also facing heartbreak in the EFL Cup, after losing their semi-final first leg 1-0 to Southampton on Wednesday evening.

Liverpool now return their attentions to their league campaign at the weekend. They face Manchester United on Sunday afternoon.

The Reds are currently second in the Premier League table, five points behind current league leaders Chelsea.

However, the Reds are struggling in terms of defensive options. They do not have much cover in full-back positions and centre-back Joel Matip is also struggling with injuries.

With their current defensive issues, Klopp may be forced to buy some more defenders in this window.

Shoot! looks at two defenders Liverpool should sign in this month’s transfer window…

Fernando Marcal

Liverpool have been playing James Milner at left-back this season; a position he is not natural at, but he has excelled there this season. However, it is necessary that Liverpool purchase a recognised left-back in this window.

Guingamp star Fernando Marcal has been in fine form this season. He has featured 18 times in all competitions for Las Costarmoricains thisterm, with five assists and five clean sheets to his name.

According to whoscored.com, Marcal also possesses the fourth highest average match rating of any Ligue 1 player, with only Ricardo Pereira, Maxime Gonalons and Oscar Trejo bettering him this campaign.

The Reds only have Alberto Moreno and Joe Gomez as their other left-back options. Gomez has struggled with injuries in the past 12 months. Whilst, Moreno has been out of favour with manager Klopp as well as being linked with a January exit.

Marcal would be a very good acquisition for Klopp as it would mean Moreno is free to go and they would also have a top quality left-back in their squad.

Sead Kolasinac

The Bosnian left-back is another option that Reds manager Klopp should consider.

Kolasinac currently plays for Schalke and despite his side’s struggles in the Bundesliga this season, the defender has been one of their strongest players.

The 23-year-old has featured 16 times for the Royal Blues this season, scoring twice and setting up four more along the way. The Bosnian has also kept five clean sheets in all competitions this term.

According to whoscored.com, Kolasinac has had the highest average match rating in the Bundesliga of any Schalke player this season. Only three players in the entire Liverpool squad have had a higher match rating than Kolasinac this campaign – Philippe Coutinho, Roberto Firmino and Sadio Mane.

Kolasinac is still quite a young player, so therefore Liverpool would be making a worthy investment if they were to approach the Bosnian.