Roberto Firmino's hamstring injury a blow for Liverpool, Brazil

Roberto Firmino will miss at least one month with Liverpool and upcoming World Cup qualifiers with Brazil because of a hamstring injury.

Firmino, named last week to Brazil's squad for matches against Colombia and Argentina, sustained the injury Wednesday during Liverpool's 2-0 victory over Atltico Madrid in the Champions League.

Losing Bobby Firmino is a blow, Liverpool manager Jurgen Klopp said Friday ahead of Sunday's game at West Ham.

We talk about weeks still and I don't know exactly but more than four, which I would consider as a serious injury.

The 30-year-old forward had missed time earlier in the season with a similar injury.

We have to see. It's Bobby, he's a quick healer, Klopp said.

Usually when you have an injury before the international break, you think OK after the international break they are ready again. That is not directly at the moment when Bobby will be ready again. So that's not good.

Firmino has scored six goals, including a hat trick against Watford, in 11 appearances in all competitions this season.

Real Madrid midfielder Vincius Jnior was named as Firmino's replacement on Friday. Brazil leads South American qualifying and plays Colombia in Sao Paulo on Thursday before facing second-place Argentina in San Juan five days later.