BRENDAN Rodgers admitted last night that his main striker Leigh Griffiths is a major doubt for tomorrow's Old Firm diary.

The 26-year-old, who has seven goals in nine appearances this season, was held out of training yesterday and instead spent the day getting a scan on the calf problem which saw him withdraw from international duty.

While Rodgers will delay his final decision on the player's participation until he sees those medical results, he appeared to be bracing himself for the worst.

Read more: Echoes of Rodgers' past life return as Kiernan and Rossiter hope to bite the hand which used to feed themThe Herald: Brendan Rodgers has asked for patience as he moulds a new Celtic team

While the Northern Irishman, named Ladbrokes Premiership manager of the month, said the absence of Griffiths would be a "big disappointment", he feels Celtic have already proven this season that they are no longer over-reliant on him and it is more important that no long-term damage is sustained.

“We’ll see on that," said Rodgers. "He’s trained this week. We had a light day Thursday and he was just away getting a scan on the injury. We’ll see how that is over the next 24 hours.

Read more: Murdo MacLeod scored Celtic's greatest goal against Rangers - and he never gets tired of hearing about it

“If he does miss the game, it will obviously be a big disappointment," he added. “But I go back when I first came in here and I mentioned the possible over-reliance on Leigh.

“What I needed to get was goals from different people and different areas of the field. You can see Scott Sinclair has goals, James Forrest has three from three in the league, Moussa Dembele has played and scored, Tom Rogic is scoring and even Scott Brown!

“That’s important and, if Leigh doesn’t make it for whatever reason, we have to ensure he is going to be ready for the season rather than put a big risk into him."

While it is doubtful if the Celtic manager was in any doubt about the importance of his first Old Firm match - as participant or spectator - and the first league encounter between these sides for four years, he had that fact underlined this week when the Strathclyde Police visited the club's Lennoxtown training complex. Rodgers, who has also experienced such police involvement when managing Swansea in the South Wales derby against Cardiff City, feels it is important that his players remember their discipline but also that the authorities remember that players are human beings and not robots.

"They had a chat with the players and then I had an individual chat with them and our security," said Rodgers. "We generally hope in games between Celtic and Rangers or any games that it never ever comes to anything like that. It is a wonderful game, a great game to be involved in, but you have a responsibility. Sometimes emotion and the stress of playing in the game can override that. But I think it is important also to understand that players aren’t machines, they aren’t robots, they have emotion as well."

Victory on Saturday would see Celtic assume a commanding position at the top of the Ladbrokes Premiership table, four points clear with a game in hand, albeit with it 34 games still to negotiate. Rodgers - whose side have already taken care of rival sides Aberdeen, Hearts and St Johnstone in a testing start to the campaign - admits there will be more than just three points at stake.

"Well, I think it is our rival, a big rival," said the 43-year-old. "If you look at our first four games if you include this one, they were all going to be against rivals for us for the league. So yes, that makes it important. Always, if you can get a win against one of your rivals early on it puts a good marker down. I think because of how Celtic were only a few months back in the semi final, for me it is a good measure to see where the team is at.

"I have said it openly - I think in the last match Rangers were the better team in the semi final," he added. "But this is is a different team and certainly a different mentality. The team needed help and needed speed. A tempo. The players have responded to the work and confidence is massive. A huge factor. This will be a good measure of where we are at."

While the loss of Griffiths would be a significant setback, new signing Cristian Gamboa in contention for an Old Firm debut after he returned yesterday from international duty for Costa Rica and Rodgers feels that the international break generally came at the right time for his side.

“When the break came, it came at a good stage for us with everything we had been through and drew a line under a great start for us," said Rodgers. "It let players recover and get real good work in. But it will be the same for Rangers and you accept it."