Both players were subsituted during Saturday's win over Fulham after picking up knocks but both are set to recover in time for tomorrow's Champions League semi-final first leg game against Chelsea.
"We have a problem with Sami. He has a knock in the head. He was dizzy so I asked him if he'd seen the third goal! He just looked at me [with a confused look]," said Rafael Benitez.
"Mascherano has one or two knocks as well but I think they will both be okay for Tuesday."
