Big games at Celtic Park are not always dictated by the opposition.

Morton come calling on Scottish Cup duty on Sunday afternoon and given the circumstances surrounding the game, the magnitude of this clash cannot be underestimated.

So much rests on the outcome since I cannot imagine that any kind of slip would be tolerated, given what has happened in the league over the last few weeks.

It will not be a big crowd that turns out to watch the game but the Celtic players need to appreciate just how massive these 90 minutes against Jim Duffy’s side are.

Like I said, it is time for leaders, for sleeves to get pushed up and for a job to get done.

Morton will set out to try and frustrate Celtic and look for openings on the break.

Celtic have to rise above the tension that will surround the game and simply go out and get a result.

we can all have our own opinions on what is the best starting XI but Ronny Deila has to put out what he believes is his strongest team.

Morton will have been encouraged by the way in which Dundee went about their business during the week and the only way I would describe what Celtic need to do is by saying it is a power-play game – they need show their mental as well as physical strength as they go all out for it on Sunday.

I don’t think there are too many within the squad who could complain if they find themselves out of the team at the weekend.

Stuart Armstrong has looked increasingly uncomfortable playing out of the left and although he was obviously happy when he first arrived at the club simply to go out and try to make an impression, you can see now that he is struggling to find his best form there.

It comes back to the problem of having too many similar midfield players.

At the same time, there has been a lack of application that needs to change over the remaining games of the season if the team are to move away from what has the potential to be a catastrophic campaign.