Lallana only made 13 appearances for the Reds last term due to injury, and was ultimately left out of Gareth Southgate's squad for the 2018 World Cup after failing to recover from a hamstring problem.
There were concerns that Lallana could face another extended period on the sidelines, but the attacker has insisted that it will only be "a brief lay-off".
"It's a minor setback, which isn't ideal, as I've been in great shape until now, but it's positive news that it's only a brief lay-off," Lallana told Liverpool's official website.
"I'm pleased I'll be back available for Liverpool, both domestically and in the Champions League during September, and then England again for the next break.
"I know I can make a significant contribution over the course of a long season and that's where my focus will remain - with so much to play for. Doing my best and giving everything for my teammates, management and supporters of club and country is all that matters.
"I'm back at Melwood now making sure my time off the pitch is as short as possible, so I'll be supporting Gareth and the boys from up here."
Lallana has only featured in one of Liverpool's four Premier League matches this term.