Moussa Dembele was an unused substitute for the second game in a row as Celtic took on Partick Thistle on Tuesday night, and for a player who was getting talked about as a potential £40million striker a year or so ago, it has been quite the fall from grace.

I feel a great degree of sympathy for Brendan Rodgers in this situation. There’s no doubt whatsoever that Dembele’s form over the whole of this season has been middling to poor. He has been nowhere near the levels he is capable of, so what are the reasons behind that?

To be fair to the player, he hasn’t ever come out and said that he wants out of the club, but there’s obviously something amiss.

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So, I can fully understand why he’s not in the team. If I was Brendan Rodgers, I’m not sure I would be playing him either, because in the times I have watched him this season, he has disappointed me. That was particularly the case in the Old Firm game just before the winter break. He was really poor, and at times, he looked disinterested.

I didn’t like the way he came off the pitch that day either, it was bordering on the arrogant. But leaving that aside, if you are looking solely at his form when he has playing, he doesn’t merit a place in the team ahead of either Odsonne Edouard or Leigh Griffiths.

And what would those two have to say if Dembele was getting a start ahead of them and turning in the sort of performances that he has done thus far during this campaign?

I’ve watched Edouard a lot, and on a couple of occasions he has really impressed me. On a couple of others, he has struggled to make an impact, but there is undoubted potential there. Then you have Griffiths, who I would be starting every week. As much as he won’t bring you the physicality of Dembele or the searing pace of Edouard, what he will bring you, and what he has brought for so many seasons now, is goals. Essentially, at the top end of the pitch, goals are what win you the game, and it’s incontrovertible that he guarantees goals.

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He has his failings as a player, but over the last two or three seasons especially, he has developed hugely from the player he was before. He’s definitely improved his all-round game, and it seems as though at times Celtic are trying to fix a problem that isn’t there, because Leigh is so reliable.

At times, I think he is undervalued, because he is capable of leading the line, he’s proven that. He might not be the most glamorous name, but you can’t take away what he has achieved in the game and what he continues to do.

No matter when Leigh has been left out of the Celtic side, he hasn’t mumped and moaned either or shown a bad attitude. He isn’t on social media taking the huff like a lot of modern footballers are prone to do. He’s just got his head down and got on with it. He is only four goals away from a century with Celtic, and the fact that John Hartson was the last striker to do that, tells you that it is no mean feat.

But this is where it gets tricky for Brendan Rodgers. If Celtic are wanting to sell Moussa Dembele and get the biggest market value for him, then by not playing him and by saying in the press that his head has been turned, as Celtic assistant manager Chris Davies has, it’s almost as if you are devaluing the player. That’s the conundrum.

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Even a year ago, I think the figures being bandied about in regard to Dembele’s value were ridiculous in comparison to what he had achieved. I know he did well against Manchester City and in big matches against Rangers, but you’d like to think that if you were playing up front for Celtic in the bread and butter stuff, you would be banging in a barrowload of goals. So, I thought back then that the fee Celtic might fetch for Dembele if they sold him would be more modest than many were suggesting, even if it would still be an astronomical amount in Scottish terms.

Now? Well, I’m not awfully sure what his actual market value is. Are you paying for potential? Because based on what he has done in the game so far and on his current contribution to the Celtic side, it’s difficult to say what he is worth.

Right now, the best solution for Celtic would be to move Dembele on and bring someone new in. If they get offered decent money for him in this window, they should take it, because I’ve never thought that Dembele was as good as others thought he was. I know he has potential, and has done well, but he is still in that bracket of potentially being a really top player.

I’ve been hugely impressed by the way that Brendan Rodgers has dealt with the media since he came up here, but this is the first time that I have seen him getting agitated with a line of questioning. And I think that is because even he doesn’t have the answer to it.