Liverpool captain Steven Gerrard could be out for three to four weeks with the hamstring problem sustained on England duty, according to the club's medical team.
The 30-year-old will undergo a scan later today but Dr Peter Brukner, head of sports medicine and sports science, confirmed the midfielder's injury was "significant".
"Steven injured his hamstring last night. He's just been in for an early assessment here and it certainly looks like a significant hamstring injury," said Brukner.
"We should have the results of the scan tonight. He's going to be out for a little while, I'm afraid.
"I'd imagine it could be three to four weeks."