THE line about your next game being your most important one is a managerial favourite. For Brendan Rodgers, is has never been truer.

The Premiership defeat to Hearts on Saturday will disappoint and frustrate the Northern Irishman but it hasn’t derailed Celtic’s bid for eight-in-a-row.

A loss to AEK Athens tomorrow night would be a far different story, however. In the Champions League, there are no second chances.

Losing to the Greeks and crashing out at the third qualifying round would be a major setback on the field for Celtic. Off it, the consequences could be even more serious.

If Rodgers can lead his side to the group stages for a third consecutive season, his case for added financial backing in the transfer market becomes cast-iron and the Parkhead board will have little option but to loosen the purse strings.

That can’t be done with only a Europa League campaign to look forward to, however, and the chances of Rodgers being heavily backed would almost completely disappear if Celtic only have a few million coming from UEFA rather than the mega bucks they have banked in the last two summers.

Celtic have had a safety net in recent years thanks to the squad they have assembled. If they missed out on European cash, they could, if required, sell a player to ease the financial burden and balance the books.

That back-up plan doesn’t exist to the same extent now, though, after the English transfer window closed on Thursday night.

With £31million in the bank at the end of the financial year, Celtic aren’t exactly in a perilous position and it is unlikely any panic buttons will be pressed if a Champions League cheque can’t be cashed in the coming weeks.

Having those funds at their fingertips is one thing, but being able to spend it is quite another and supporters will be split into a Rodgers camp and a board camp over that debate.

The task of transforming Celtic from a side that are dominant domestically into one that is competitive on the continent is far from easy, and far from cheap.

The £9million spent on Odsonne Eduoard was a start, but it will take four, five, six players of a similar standard, and of a similar price, to add the quality that Celtic need to make more of an impression in the Champions League.

When it comes to speculating to accumulate, that is one significant gamble and it would be understandable if it was one Peter Lawwell felt he couldn’t take.

Rodgers may have brought in the thick end of £60million during his first two years at Parkhead but it would be folly for Celtic to splurge a significant portion of that on transfer fees and wages when there is no guarantee of a return in Europe.

It won’t take anywhere near that level of spend to keep Celtic ahead of the curve in the Premiership but a balance must be struck. If you stand still, you are in danger of going backwards and that is why missing out on John McGinn has caused such consternation.

The secret to Rodgers’ success over the last two seasons has been his ability to coach and cajole, to get the best out of what he inherited and make players better.

Some signings, like Moussa Dembele and Olivier Ntcham, and Scott Sinclair to an extent, have paid off, while there is more to come from Jack Hendry. Rodgers’ record in the market isn’t that impressive, though, and there have been more misses than hits.

Marvin Compper and Charly Musonda are the headline failures while another loan signing, Patrick Roberts, didn’t prove value for money second time around. Eboue Kouassi hasn’t lived up to his £3million price tag and Jonny Hayes, Cristian Gamboa and Scott Bain are Premiership squad players, not European stars.

How the money has been spent is, to an extent. as pressing an issue as how much has been made available at Parkhead.

The chequebook will remain in Lawwell’s hands but Rodgers’ financial fate is very much in his own as he bids for a Champions League hat-trick this summer.