Liverpool keeper Alisson has been ruled out for "for the next few weeks" with the calf injury he picked up in the season-opening win against Norwich City, says manager Jurgen Klopp.

The Brazil international, 26, went off after 39 minutes of the 4-1 victory and was replaced by summer signing Adrian.

Liverpool could sign veteran keeper Andy Lonergan on a free transfer, with third-choice Caoimhin Kelleher not yet fully fit after a broken wrist.

"It's not too cool," said Klopp.

"It's a calf injury which takes Alisson out for a while."

Alisson was a key figure for the Reds in his debut season after joining from Roma, helping them win the Champions League and finish second in the Premier League.