The outcome of the first Old Firm game of the SPL season rarely reveals which direction the trophy will be heading in at the end of the campaign, but I think this game in particular will show us who is on pole for the race ahead.

It’s hardly been an ideal start to the season for either of the Glasgow rivals, but Tony Mowbray at least can plan for the game knowing his men will still be top of the table even if they lose at Ibrox, and mentally that is important. On the other hand, a defeat for Rangers would be disastrous for Walter Smith and the fans – slipping seven points behind even at this stage would mean an uphill battle the rest of the way. Quite simply, the Gers cannot afford to let that happen.

Rangers have not scored in three SPL games, and against Sevilla in the Champions League they were put to the sword in the second half, so it will be intriguing to see what kind of a response they will produce on Sunday.

One man who needs to step up his game is Pedro Mendes. The former Portsmouth man hit the ground running when he arrived in Scotland, scoring a cracker against Celtic in an emphatic win at Parkhead. There have been few glimpses of that kind of form in the past few weeks, and at Rugby Park he was sent off against Kilmarnock, leaving Rangers a man down for the majority of the game.

Mendes links play together brilliantly when he’s on form, but since Barry Ferguson departed he seems to have dropped deeper, taking the ball from the defence rather than receiving it where he is at his dangerous best – near the strikers. Ferguson was always the man who brought the ball out from the back and that allowed Mendes to take on a more forward position, but right now the Portuguese playmaker seems all too content to just receive and make simple passes in the middle of the park and inside his own half.

Perhaps this game will bring out the old Pedro Mendes – he seems to operate on a higher level on these occasions anyway. It’s the other games though that so often decide the league championship, and therefore Mendes must perform more consistently. If he is on-song, expect Rangers to create a lot of chances – he’s the key figure for the Gers in my opinion.

Celtic arrive at Ibrox off the back of a home draw with Rapid Vienna on Thursday night, and they too have yet to hit top form this season. A week ago live on ESPN they defeated St Mirren, but it wasn’t vintage Celtic, and Mowbray made it clear to me after the game that he expects better – an honest assessment from the manager.

I admire Mowbray for attempting to get his team to play slick, attacking football but his frustrations suggest his players aren’t executing his game-plan well enough. Mowbray is still experimenting with his side in defence as well, his centre-half pairings have changed in the past few weeks, and that is another area he’ll have to think long and hard about ahead of this game. Does he pick McManus and Caldwell (as he did midweek), or is it Loovens and McManus (as at St Mirren Park last week)? It’s something he’ll have to get right, and it’s a big call.

Both managers have tough decisions to make ahead of the game, but Walter Smith’s dilemma may be at the other end of the pitch. Up front his men have not been firing on all cylinders and Kris Boyd has not been sharp of late. The Rangers boss will need to decide who the best partner for Kenny Miller is on Sunday, assuming the Scotland international is fit enough to start.

Of course Smith has seen it all in these derby matches, and his experience (and the fact that Rangers are at home) perhaps gives the Gers a slight advantage. The fact that they’ve also had one day more rest than Celtic may also be a factor. Then again, who knows what will happen, it is after all the Old Firm, the derby of all derbies, and the outcome is almost impossible to predict.