Flu-ridden Gerard Houllier has acknowledged Liverpool are "going through difficult times".
The Liverpool manager's admission followed Southampton's 2-1 victory at Anfield as Liverpool slumped to a fourth league home defeat of the season.
Houllier has been under pressure after chairman David Moores wrote in his annual report that Champions League qualification was the "minimum acceptable target" for the club.
Southampton's defeat leave Liverpool ninth in the table, three points behind fourth-placed Fulham, who have a game in hand.
Brett Ormerod gave Southampton a second minute lead and Michael Svensson extended the visitors' advantage midway through the second half before Emile Heskey grabbed a late consolation goal.
Houllier said: "I understand the fans' frustration, we are suffering together. But
we just have to keep our heads up and keep going, but I admit this is a
difficult period, I must say, for us.
"We were without six first-teamers and all our first-choice strikers. In the
end we paid for a lack of finishing.
"Only Chelsea with their vast squad, could cope with the loss of as many
players as we are having to handle.
"If Manchester United lost Ruud van Nistelrooy and Paul Scholes and Arsenal were without Thierry Henry and Robert Pires, they would struggle too.
"We know now that we have to dig deep, this is a tough period for us. I
believe the fans who were here at least understand the problem even if they are frustrated. I doubt whether the phone-in fans will understand."