The Brazilian goalkeeper limped off the pitch towards the end of the first half as Liverpool started their 2019-20 Premier League season in style, defeating Norwich 4-1 at Anfield.
Klopp says Alisson will be out for a number of weeks, meaning he will miss out on Saints.
This could be good news for Southampton fans. Alisson is one of the key reasons behind Liverpool’s resurgence which saw them win the Champions League and almost take home their first Premier League title.
OPINION: Five realistic things we want from Southampton this season
READ: Kevin Danso says Ralph Hasenhuttl was “pivotal” behind Saints move
READ: Ralph Hasenhuttl brands Southampton “disappointing” in Burnley defeat
READ: Saints Under-23s beat Manchester City in stirring comeback
“[It’s] Not too cool. It’s a calf injury which takes him obviously out for a while,” Klopp told Liverpoolfc.com.
“I don’t want to make now [an] exact prognosis on when he will be back but it will not be Wednesday for sure, so now then we have to see. It takes a while, it takes a couple weeks for sure, and we have to see.
“I saw already like ‘six weeks’ and stuff like this, but Ali was not a lot injured in his career so I would like to wait a little bit to see how he develops in that process now, but he is not in for the next few weeks.”