Celtic boss Neil Lennon has revealed that he has doubts over the potential involvement of one senior star ahead of a crucial UEFA Champions League clash with Benfica.
He has, however, refused to reveal the identity of said player.
Scott Brown (hip), Joe Ledley (groin) and Gary Hooper (hamstring) are all nursing knocks.
The trio have, however, made the trip to Portugal and will hope to be involved at some stage.
Benfica playmaker Pablo Aimar is a doubt after he was nowhere to be seen during a training session open to the media on Monday.
However, Maxi Pereira, who has been sidelined by a thigh injury since 7th November, was put through his paces.
Carlos Martins (thigh), Eduardo Salvio (foot), Ezequiel Garay and Enzo Perez also came through the session unscathed and will be in Jorge Jesus' thoughts.