The England right-back sustained a severe ankle sprain during Sunday's 1-0 home win over Manchester United which forced him out of this weekend's World Cup qualifiers for the Three Lions.
Johnson will undergo treatment at Melwood but the Reds have not yet put a date on his return.
"After being examined by the club's medical staff at Melwood, Johnson is required to rest his ankle this week," read a statement on the club's official website.
"A further review will then take place to check stability and decide on further management.
"Therefore, Liverpool have not put a timeframe on Johnson's return to fitness at this stage."