Gerrard is expected to spend several days in hospital while he is given antibiotics to cure the infection before returning to the club’s Melwood training ground to continue his rehabilitation.
The England midfielder hasn’t played for Kenny Dalglish’s side since March when he had surgery in a bid to cure a recurring groin problem.
Gerrard has missed all of Liverpool’s pre-season programme, with the infection further slowing an already difficult recovery after the operation.
The 30-year-old will now be ruled out of Liverpool’s opening three Premier League fixtures against Sunderland, Arsenal and Bolton.
“Steven Gerrard today began a course of antibiotic treatment for an infection related to an ongoing groin problem,” a statement on Liverpool’s website read.
“He is expected to remain in hospital for several days while the precautionary procedure is completed.
“The player will then return to Melwood to continue his rehabilitation programme and is expected to be available for selection in September.”
Gerrard’s spell on the sidelines will also preclude him from featuring in England’s friendly against Holland on August 10.
More worryingly for England coach Fabio Capello, there is little chance of Gerrard having any playing time before his country’s two crucial Euro 2012 qualifiers against Bulgaria and Wales.
England visit Bulgaria on September 2 and host Wales four days later as they try to maintain their position on top of Group G in the race to qualify for the finals in Poland and Ukraine.
Meanwhile, Liverpool’s disappointment over Gerrard’s absence will be partially offset by the news that goalkeeper Jose Reina is ready to return after surgery on a double hernia in the close-season.
The Spanish star has not featured so far during pre-season but is set to face Valerenga in a friendly in Norway on Monday.
“The target is to play in Valerenga, and then after Valencia there is one more week and that should be good enough to get that fitness,” Reina said.
“We didn’t want to rush it – there was no point in doing that. I’m totally recovered now, training with the team as normal and looking forward. I can’t wait to play again.”