Liverpool captain Steven Gerrard will be out of action for three weeks after a scan revealed a torn hamstring.
Gerrard was replaced after 16 minutes of Wednesday's FA Cup replay against Everton, which Liverpool lost 1-0.
The midfielder will now miss Saturday's match against Portsmouth, England's friendly against Spain next week and the visit of Manchester City.
Gerrard, 28, also faces a race against time to be fit for the Champions League tie against Real Madrid on 25 February.
bracewells-wedgeThe absence of Gerrard is a blow to Liverpool's title credentials having scored 11 goals for them in the league this season.
Liverpool are two points behind champions Manchester United, who have played a game less.
"A scan today has confirmed a tear in the hamstring of Steven's left leg," a spokesman told the club's official website.
"He will be out of action for about three weeks."
It is a blow to Liverpool manager Rafael Benitez who did not add to his squad in the January transfer window.
The Spaniard also came under criticism from some fans after selling striker Robbie Keane back to Tottenham for £12m.
It has left Liverpool short of forward options and the absence of attacking midfielder Gerrard further limits Benitez's options.
Star striker Fernando Torres is also battling his way back from a hamstring injury and is still short of full fitness.