Jürgen Klopp has revealed that Liverpool midfielder Lucas Leiva could be out for around five or six weeks with a quad injury suffered in last weekend's Capital One Cup penalty shootout.

The Brazilian faced up against Manchester City striker Sergio Agüero for 120 minutes and his exertions led to the Reds' No.21 sustaining a slight knock, which was then worsened when he stepped up to take his spot-kick at Wembley.

The injury meant he was absent for Jürgen Klopp's side's emphatic 3-0 Barclays Premier League win over City in midweek, but Klopp confirmed that he could miss at least another six games - including Sunday's trip to Crystal Palace.

Lucas out for at least next few weeks

Lucas picked up a knock after a terrific individual performance against City. (Picture: Getty Images)
Lucas picked up a knock after a terrific individual performance against City. (Picture: Getty Images)

Issuing a fitness update at his pre-match press conference at Melwood on Friday, Klopp said that Lucas is "really unfortunate" and explained that his knock is "a little bit more serious."

"I've never heard about an injury you get like this, from a penalty," admitted the Reds boss about the 27-year-old's knock, saying that it was "only because he was a little bit injured before." 

Klopp added that Lucas "didn't feel too much" but said that "it was done" as soon as he took the penalty, insisting that whilst he doesn't know "exactly" how long he will be out for, it's "not too good" and he's set for "five or six weeks [out]".

Sakho and Sturridge likely to be in the team for Palace

Sakho was frustrated after being substituted as a precaution in the cup final. (Picture: Getty Images)
Sakho was frustrated after being substituted as a precaution in the cup final. (Picture: Getty Images)

The German did have a more positive update on defender Mamadou Sakho, who returned to training after going off in the cup final after a clash of heads with Emre Can and missing the midweek win over Manuel Pellegrini's City.

Klopp said that Sakho "did a little bit" on Friday "for the first time" but said that they "didn't really do a lot" because it was still only two days since their last game and therefore still a recovery session.

"The only session we have is tomorrow [Saturday]," he said, insisting the club "have to see how he is then" but said he at least "did a little bit more" in his first session back. 

Asked about Daniel Sturridge, who missed Wednesday's game after going down with cramps late into extra-time of the previous game, Klopp assured supporters that he "trained completely normally."