Celtic manager Martin O'Neill will wait for news of striker Chris Sutton's young son before deciding if the player can be included for the Old Firm derby on Sunday.
The former Chelsea and Blackburn forward missed the UEFA Cup tie in Valencia after his child, James, was taken to hospital with respiratory problems.
Sutton has returned home but O'Neill will wait until they hear more news before deciding on the player's inclusion.
But the Parkhead club have appealed that the privacy of the Sutton family is respected at a difficult time.
"We are asking the media to respect the privacy of the family," said a club spokesperson.
Welsh international John Hartson will deputise if Sutton is unable to make the game.
Central defender Joos Valgaeren is unlikely to play through a lack of match practice although O'Neill will allow the player more time to decide on his inclusion.
Midfielder Alan Thompson, another injury doubt, has shown some improvement but, again, O'Neill will make a decision tomorrow.
Rangers manager Dick Advocaat, meanwhile, insists hot-headed Fernando Ricksen will keep his cool against Celtic.
The fiery Dutchman was red-carded during their vital first-leg, third round UEFA Cup tie against Paris St Germain last night.
Ricksen endured a turbulent first season at Ibrox last term when his performances and discipline were questioned by the Ibrox faithful.
He became the first player in Scottish football history to receive a retrospective red card when video evidence showed that he aimed a kung-fu style kick at Aberdeen's Darren Young.
Just two months later, during the old Firm derby at Parkhead in February, the defender saw red again.
Earlier this season Ricksen claimed that he now had his explosive temper under control and his performances on the park this season seemed to have backed that up.
Despite his moment of madness against PSG, Advocaat claims he has no fears about throwing Ricksen straight into the white-hot atmosphere of Sunday's Old Firm derby.
He said: "I will speak to him tomorrow when we go to the hotel. I think Fernando is one of the players who has played very consistently the whole season to quite a high level.
"But yesterday, unfortunately, it was a moment again which he also showed last season.
"But I will speak to him tomorrow and I think he will handle that good.
"He showed last season that he was very calm and he was very relaxed."
The match is live on Sky Sports at 12 noon.