Liverpool face group E leaders Lyon in the Stade Gerland knowing that only a victory will keep alive any realistic hopes of staying in the Champions League this season.
"Fernando is improving, we do not want him to have an operation so we are managing his fitness carefully," said Benitez.
"But he is getting better. He had some pain after he played, and scored, against Manchester United. But he was better after the Fulham game at the weekend, although he could still feel something wrong.
"I hope that he will be even better for this match. I said recently that 80 per cent of Fernando can win matches, I hope that is the case again."
But it is his own position as Liverpool boss that Benitez knows will come under further tough scrutiny if his walking wounded do lose to Lyon for the second time in a matter of weeks.
He says: "The players are working very hard, they are positive and determined. They know this result is important for the club, for everyone.
"But our fans have not turned. They are clever people, they know the position the club was in when I arrived and they know what position it is in now, they know this is the only way.
"It is important for everyone to see the bigger picture, I am sure things will change in a few weeks when we have our players fit again. When we have our big players available, everything will change.
"I do not accept that we have not signed good players, some may not have settled as quickly, but we are doing a good job."