Dejan Lovren
Dejan Lovren and Philippe Coutinho both suffered hamstring injuries on a mixed night for Liverpool in StokeAFP

Jurgen Klopp has admitted that Liverpool may be forced to delve into the transfer market this month in order to solve a defensive crisis that was further exacerbated during the Capital One Cup semi-final first-leg tie against Stoke on 5 January.

A first-half strike from substitute Jordon Ibe means that the eight-time winners will take a slender lead back to Anfield for the return clash later this month, but an otherwise positive night was tempered by both Philippe Coutinho and Dejan Lovren limping off with hamstring issues before the break. Those problems are just the latest in a long line of injury woes for the club, who are already without a number of important first-team players including captain Jordan Henderson and key striker Daniel Sturridge.

Although Liverpool have attacking players to try and compensate for the costly loss of Coutinho, the injury to Lovren will be far tougher to deal with as it comes at a time that Klopp is also without Martin Skrtel due to a similar problem sustained against Watford last month and Mamadou Sakho also missing the trip to the Britannia Stadium with a minor knock to his knee. Brazilian midfielder Lucas was forced to deputise alongside Kolo Toure as a makeshift defender for most of the match, although his manager appears realistic that the hunt for proper reinforcements will now need to become more urgent.

"In this situation with no centre-backs fit I would say [transfers] is something we could look at," he was quoted as saying by Liverpool's official website during his post-match press conference.

"It's a big shadow over the game for us, the injuries. I don't know how serious and we have to wait for this. At 1-0 nothing is decided in a tie like this. I was really angry a few days ago but now I'm proud."

Klopp, who watched his side throw away the chance to chalk up a third consecutive Premier League win last weekend as headers from Michail Antonio and Andy Carroll condemned Liverpool to a 2-0 defeat at West Ham, also revealed that Sakho is unlikely to be fit for the FA Cup third-round trip to Exeter City on 8 January. Toure could feature against the League Two outfit, however, with the German remaining optimistic that his only fit senior centre-back was suffering from cramp late on against Stoke.