Both players were expected to miss the rest of the campaign, but they are now on the comeback trail and Houllier has not ruled them out returning before the end of the season.
Litmanen has missed the last eight games with a broken wrist, whilst Barmby has been sidelined with a troublesome ankle problem for the past three weeks.
Finnish striker Litmanen has begun light training and Barmby, who has had his ankle in plaster, is set to see a specialist to find out if he needs to undergo an operation.
The possible return of the key duo would be a major boost to The Reds, who have five league games to play as they try to win a place in next season's Champions League and both the FA and Uefa Cup finals to contest next month.
"Maybe with a bit of luck both Nick and Jari will be available in the last week of the season," said Houllier.
"Jari has started doing some light training and a bit of ball work. He will have a plaster-cast put on his hand at the beginning of next month and we'll see.
"Nick is still in plaster but he will see a specialist at the end of the week. I still don't think he will need an operation."
Meanwhile, long-term injury victim Jamie Redknapp has boosted his hopes of playing a role in Liverpool's chase for honours, after successfully coming through his reserve-team outing.
The Liverpool skipper, who has been out of action for almost a year after breaking down during training with England prior to Euro 2000, played for an hour of the reserves' 0-0 draw with Blackburn on Monday night and even hit the post.
Redknapp was delighted to make his long-awaited return to competitive action.
"I can't tell you how good it felt to be out there playing again," Redknapp told the club's official website.
"It was brilliant for me to be involved. The biggest compliment people paid me after the game was when they said it didn't look as though I was carrying any sort of knee problem.
"I have to admit there have been times over the months when I wondered if this night would ever come. It as at those times you look for support and encouragement from the medical team and your surgeon. They have all been fantastic and if I can now go on playing for another six years or more then I will owe them everything for getting me through this.
"I'm not going to set my sights too high for this season. If I can get more reserve games under my belt then that will be good enough for me."
The only bad news for Liverpool was the new injury picked up by Vegard Heggem in the game with Blackburn.
The Norwegian international, who has been plagued with thigh and hamstring injuries all season, suffered a groin strain and is expected to miss the rest of the forgettable season for the full back.
Meanwhile former Barcelona coach Johan Cruyff has slammed The Reds over their style of play in beating the Spanish giants last week in their Uefa Cup semi-final.
The Dutch legend branded Houllier's side "horrible" after securing their place in the Uefa Cup final with a 1-0 win over Barca.
Cruyff is not a big fan of the Merseysiders and he has compared them to Bayern Munich, who he has also labelled as a negative team.
"Liverpool are just like Bayern Munich," said Cruyff. "They're all about name and prestige but, in footballing terms, we're talking about two horrible teams.
"In my opinion, if a team is incapable of stringing three passes together it is horrible.
"The qualities of Bayern are organisation, strength, defending, destroying and working on maintaining a minimal advantage, but they're German."
