Leinster backs coach Felipe Contepomi says there is still a "question mark" over James Ryan's return date from injury.
The Ireland lock suffered a calf injury during the Guinness Pro14 match against Connacht on 4 January.
The player missed Sunday's Heineken Champions Cup win over Lyon and is a doubt for the final pool match against Benetton Treviso on Saturday.
"It's still a question mark. Definitely, he's making improvements but he got injured less than 10, 12 days ago," said Contepomi.
"It's a muscular injury, so you have to take it day by day, even hour by hour.
"And if he's fit, good for us, good for him. But definitely he has to prove he's fit to play. So it's still a question mark."
Meanwhile, Contepomi also ruled Johnny Sexton out of contention for the match against Benetton but emphasised that the Ireland out-half is making good progress ahead of Ireland's Six Nations campaign which gets underway on 1 February against Scotland.
"I think he's ruled out of Benetton. But I think he's doing great progress and hopefully for Irish rugby and for Leinster rugby, we will see him soon on the pitch," he said.
The province have already assured themselves of a place in the last-eight of the Champions Cup. But the outstanding issue is to make sure of a home quarter-final and victory over Benetton will secure that target.
"It's a huge advantage, definitely," said Contepomi of the importance of a home quarter-final.
"It gives nothing for granted but it's definitely an advantage and if we can have that small advantage, I'll take that every day."