Fitness latestUpdates on Firmino, Jones, Gomez, Keita, Milner, Fabinho and Thiago

The Brazilian picked up the issue after coming on at half-time of Wednesday’s 2-0 victory at Anfield and is facing a period on the sidelines.

Klopp told Liverpoolfc.com on Friday: “Bobby is not good news with a serious hamstring injury, really unfortunate. We don’t know exactly how long he will be out but it will be not now after the international break directly. We have to work on that.”

Meanwhile, Joe Gomez (calf) and Curtis Jones will also miss Sunday’s trip to West Ham United, but the boss hopes the duo will be available again soon after the international break.

Klopp continued: “Curtis is a completely different story [to Firmino], he was very unlucky in training – he got a finger that scratched the eye. I had a lot of injuries to players in my career, that was not involved. He is on the way back but we have to see how long exactly.

“He will be back after the international break, for sure, but in the international break we have to see when he can start doing proper stuff again.

“And Joey, hopefully after the international break as well.”

It’s a similar situation regarding Naby Keita and James Milner (both hamstring), too, with the manager saying during his pre-match press conference: “We will see. For them, I have hope for after the international break but I don’t know exactly.

“We have to wait. That’s two weeks and a few days from now on, so that’s what I would really wish for but I cannot promise that. But that’s what we are working on.”

Fabinho and Thiago Alcantara are set to be in contention for this weekend’s visit to London, however, after both made their returns from injury against Atletico.

“Very important, you see that. Fab was clear – he was not that long out – that he can maybe go, how we decided then 60 minutes,” Klopp stated.

“And swapping that with Thiago was probably exactly the right thing to do, now they should be both a big step ahead, so all good.”