Say what you will about Brendan Rodgers – and his critics have taken their chance this season to sharpen their knives – but he knows his way around an Old Firm fixture.

The Celtic manager clearly hasn’t missed that criticism, and he didn’t miss his detractors in his post-Rangers debrief after claiming his 13th win from 17 against the Ibrox club, with just one defeat along the way.

Rodgers has chosen the moments after wins over Rangers at Celtic Park to remind everyone that he has been the top dog in Glasgow whenever he has resided in the city. In December, he pointed out that he has seen all five previous Rangers managers he has faced off the premises, and on Saturday, he hit back at the notion put forward by pundit and ex-Celtic striker Chris Sutton that he has been ‘going through the motions’ this season.

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He certainly hasn’t lacked bite in his post-match analysis, then, even though his team have at times this season. Their performance on Saturday though was a reminder that when they have their key men fit and firing, they are a formidable outfit.

His Celtic team may still have some way to go to match the previous iterations of ‘Brodgeball’ that the fans enjoyed during his first spell in charge, but they have certainly come good at the critical moment. In fact, it could be argued that the season will be finishing at an inopportune moment given the trajectory that Rodgers’ team seem to be on.

The question now is whether they can maintain the momentum they have built up into next season, so that they avoid the teething problems they went through after Rodgers’ return in the summer. And the only way they will be able to do that is to back their manager in the coming transfer window.

Celtic fans won’t want to consider it, but there is bound to be a rather large Matt O’Riley-shaped hole in their midfield, for a start.

Given that Atletico Madrid were sniffing around him in January, the level of club coming back in for the Danish international in the summer will be such that a certain level of fee can be commanded, and that will provide some comfort to Celtic and their support. But only if a sizeable portion of it is reinvested in ensuring that a quality replacement is identified and recruited.

Rodgers has hammered home the point ad nauseum this season that he needs quality, not more project signings, if his team is to progress. A reshaping of the recruitment department is already underway, with Mark Lawwell departing and South American scout Mark Cooper coming back on board.

Rodgers has even said that it is his job to persuade the Celtic board to loosen the purse strings. They shouldn’t need convincing. The way that Rodgers has pulled this team together when they needed it most should be all the evidence they require that they have the right man in place to take them to the next level, if they give him the tools.

There will of course also be a vacancy in the goalkeeping position with Joe Hart retiring. Liam Scales has surpassed all expectations to become a mainstay at centre back, but it is an area that could still be strengthened, with neither Maik Nawrocki nor Gustaf Lagerbielke looking to have any future at the club.

The left back position may well be addressed too. Greg Taylor is unfairly maligned at times, and Rodgers is a huge fan of the former Kilmarnock man. He has become a key member of the team and the dressing room, but competition is required at the very least.

Up top too, reinforcements will be required. Kyogo Furuhashi has looked more like his old self of late, and recruiting a striker of greater quality than the Japanese to lead the line may be a stretch too far for Celtic’s budget.

But a decision will have to be made over Adam Idah, who is set to return to Norwich City after the expiry of his loan deal. He has shown some real quality in flashes, and he is a step up from Oh Hyeon-gyu when Rodgers wants a physical presence up top or wants to give Kyogo a breather.

Whether he has it in him to improve the main striking position though is up for debate. And whether he would want to sign a permanent deal to play that understudy role, and whether Celtic would want to shell out £5m to fill it, remains to be seen.

The key point though is that if Rodgers wants to push that deal through, he should meet minimal resistance from upstairs. And that goes for just about anyone else he wants to bring in too.

Rodgers isn’t naïve. He knows the financial limitations he is working within. But if Celtic want to progress and make a better fist of things in the Champions League, for instance, they must use some of the money they will receive for participating in it to give their manager a fighting chance.

Rodgers has made it plain over the weekend that he doesn’t take kindly to being treated like a novice. But he also won’t stand being taken for a fool by his own board.

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Celtic have (all but) won the league this season in spite of their flaws and their missteps over the last few transfer windows. Rodgers has shown he can firefight and still emerge victorious. He has won over many of the cynics within the support who didn’t want him back at the club as a result.

He should also have won over any remaining doubters within the club that he might just know what he is doing. And he should be backed as such.