"He's improving, but we cannot put any pressure on it. It was a really serious injury in the calf, and it's now much better. That's good for us and good for him, but we don't know (when) exactly. The target was always after the next international break he could be ready, but we don't know. Hopefully everything will be fine for the rest of the season. That is the plan."
The news will be a blow to the European champions. Alisson has developed into one of Europe's best stoppers and was named UEFA's Champions League Goalkeeper of the Year for 2018-19:
He has already missed three Premier League games and the UEFA Super Cup for the Reds, and he will now be forced to sit out some more crucial fixtures.
Liverpool take on Newcastle United, Chelsea, Sheffield United and Leicester City in the Premier League and also face Napoli and Red Bull Salzberg in the Champions League before the international break.
Alisson had been a model of consistency for the Reds since joining from Roma in July 2018 and did not miss a single minute of top-flight action last season:
Summer signing Adrian will continue to deputise for Liverpool. The 32-year-old arrived at Anfield as a free agent in August and has made a promising start to his Anfield career:
Adrián San Miguel @AdriSanMiguel
AUGUST 2019‼️ First month under @LFC shirt to remember!!😍 •5th... Liverpool FC 📝🔴 •9th... Debut & 3 points ✅ •14th... Super Cup🏆🥇 •17th... 3 points ✅ •24th... 3 points ✅ •31st... Clean Sheet & 3 points ✅ #LiverpoolFC #LFC #YNWA #Football #ADR13N https://t.co/zyrR1XSUzl
The goalkeeper has also been working hard over the international break. Liverpool goalkeeping coach John Achterberg has said Adrian has undertaken extra training sessions to "to help him and keep him fit and ready," per James Carroll at Liverpool's official website.