Leigh Griffiths remains injury doubt for Celtic v Rangers
Celtic striker Leigh Griffiths is in an Old Firm fitness race after having a scan on his hamstring injury.
He missed Scotland's 5-1 World Cup qualifying win over Malta on Sunday but returned to training earlier this week ahead of Saturday's game with Rangers.
"He's looked good in training but obviously he didn't train today," said manager Brendan Rodgers.
"Once we get the scan through, we need to look at what the risk will be for him playing in the game."
Left-back Kieran Tierney also dropped out of the national squad but Rodgers said the teenager "will be fine" to play at the weekend.
Griffiths scored 40 goals last season and has started this campaign impressively, finding the net seven times in nine games.
"He obviously wasn't able to go away with the international team he suffered a little bit in the last home game," added Rodgers.
"He had a week's rest, then he's been training with us this week.
"It was a light training day today so there was no need to risk him on that
"He was having a scan just to see how the injury had reacted over the past 10 days and we'll see how that is over the next 24 hours or so.
"But he's been in a great form. But if for whatever reason he didn't make it you've seen with the squad and what I said at the beginning of the season was that we need to have goals all round the team and that's how it's been for us."
Patrick Roberts missed a golden chance in last season's Scottish Cup defeat to Rangers and the winger is looking forward to an opportunity to make amends.
The on loan Manchester City player could not find an open goal when Celtic were leading 1-0, with Rangers going on to win the semi-final on penalties.
But Roberts is confident he won't slip up if he has another good chance on Saturday.
"For myself I know it was a bad miss," he said. "I tried to be too perfect and it didn't come off. Next time it will be in the back of the net!
"I'm all excited for this game. They beat us the last time and it wasn't the best of performances from us so we hope to put that right at Parkhead.
"Games like this is what I came up here to do, big games and big performances are needed."