Liverpool manager Rafa Benitez is waiting on the results of a scan to discover the extent of Yossi Benayoun's hamstring injury.
Benitez is making plans for the second leg of Liverpool's last-16 UEFA Champions League meeting with Real Madrid at Anfield on Tuesday, and also has concerns regarding the fitness of star striker Fernando Torres.
But Benayoun, arguably the Reds' best performer since the turn of the year and the hero of the 1-0 first-leg win at the Bernabeu, is the major doubt after the Israel international sustained a hamstring setback.
"Yossi has a hamstring problem and we will know more after the scan," Benitez told Liverpool's official website on Monday.
Benitez is more optimistic that Torres will be able to play a part as Liverpool look to book a quarter-final spot.
He continued: "Fernando is training but not in the full sessions. We are doing special sessions with specific work with some players. Hopefully he can train today and then we will see.
"It depends on his reaction after the session and then again tomorrow. I think he can be part of the squad and maybe he can play some minutes, but I can't guarantee how much."
The Reds will also make late fitness decisions on full-back Alvaro Arbeloa and central defender Daniel Agger.
"It's the same for Arbeloa and Agger. We have two more training sessions before we have to decide," added Benitez
However, winger Albert Riera will definitely sit out the clash with Real as the Spaniard is suspended following a booking in the first leg.
"We have known that Riera will be suspended and we have two or three options in that position for this match," concluded Benitez.