Against Manchester City he added another 33 minutes to two previous second-half substitute appearances as he continues his comeback from two months out with an ankle infection.
It seems unlikely he will start against Oldham but Wednesday's semi-final first leg back at the Etihad Stadium looks more realistic.
"Stevie is improving his level of fitness all the time but we have to be very careful as to how he prepares," said Dalglish.
"It would be wrong of us to be negligent and throw him in and undo all the good work he has done so far.
"We would love to have him back fit and well but we just have to be a bit patient."