Liverpool boss Roy Hodgson believes his team was suffering from fatigue after their 1-1 draw with Wigan Athletic.
Hodgson named the same side which beat Chelsea 2-0 on Sunday but the players tired quickly and they were not helped by Raul Meireles battling through the first half with sickness before being replaced at half-time.
"You can put it down to Napoli, Blackburn, Bolton and Chelsea with a small squad of players," said the Reds boss in reference to a succession of games in a short period of time.
"We have got five injuries at the moment, that is what we have and are using.
"Meireles was sick. I don't know how long it will take him to recover but he was complaining of it just before the game.
"He wanted to play and took some tablets and that got him through the first half but there was no option but to bring him off.
"Hopefully we will get some players back soon and that will help us.
"Now we have to work hard to get people back in the right physical and mental frame of mind.
"We always knew this was going to be a tough test, they are not a bad team at all."
