Liverpool captain Steven Gerrard is expected to be sidelined for up to a month with an ankle infection.
The 31-year-old was seen leaving hospital on Sunday on crutches with his right leg in plaster.
The midfielder missed his side's 2-0 win against West Bromwich Albion on Saturday.
After the match, Reds boss Kenny Dalglish said that they would know the extent of the problem during the week.
Gerrard had only recently returned to action following a six-month layoff with a groin injury.