It had been thought that the Wales flanker could miss the remainder of the season after he suffered knee ligament damage in the RBS 6 Nations finale against France in March.
He will not feature for the Blues against Connacht on Friday but could return in the Welsh derby against Newport Gwent Dragons on April 29.
"Sam will hopefully be available for the Dragons game," said Blues director of rugby Dai Young.
"You've got to set yourself realistic targets. If things don't progress as quickly as possible, players don't play. It's as simple as that. We are not going to risk players.
"But Sam is moving along nicely and the Dragons game seems a sensible target."
The fitness is particularly timely given that the game falls on the same day as the Royal Wedding to which fellow openside Martyn Williams has been invited.
But Young has dismissed the notion that the positive fitness reports played a role in his decision to grant Williams permission to attend.
"It's a unique, once-in-a-lifetime opportunity for Martyn," said Young.
"I would be quite mean to stop him going and obviously we will have a number of options that would be available for the Dragons game."
British & Irish Lions prop Gethin Jenkins could also make his comeback in the clash. The loose-head has been sidelined for three months following the toe surgery that ruled him out of the entire Six Nations.
Jenkins had been targetting a comeback this weekend but his return date has been set back.
"We were hoping for Gethin to be available for this game, but he's not quite where he wanted to be," said Young.
"He's running. It's just that pressure point from the scrum is the issue more than anything.
"Realistically the target has moved back a couple of weeks to the Dragons game now."
But John Yapp and Chris Czekaj are back in contention for the must win clash. The Blues lie four points adrift of the play-off places but crucially hold a game in hand.
"We've got some difficult games and if we want to get in that top four we know the challenge that's in front of us," added Young.
"Connacht over there is a very tricky game. They have spoiled many teams' parties. They will certainly be out to do that.
"They've got a proud record at home. It's a place we traditionally struggle, so I don't see them doing us any favours.
"If we want to be there, we've got to win all our games. It's as simple as that really. If we do win every game, we will be there or thereabouts.
"There are a number of games left. The most important one is the next one and this is the big one for us.
"We go over to Galway with everything to play for and knowing it's a must-win game."
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