The signing of Jonny Hayes was expected to be the start of a busy summer for Celtic. Signed from rivals Aberdeen, the Irish winger was the Scottish champions’ first signing of the transfer window and certainly not expected to be the last. Now, however, transfer market expectations have been somewhat dampened.

Hayes almost certainly won’t be Celtic’s only summer signing. But by Brendan Rodgers’ own admission, only one more player will be signed before the all-important Champions League qualifiers. Only after those qualifiers will the Hoops really commit to finding quality in the transfer market.

“Jonny was one and there is another I would hope we can get in,” the Northern Irishman explained in an interview with Celtic TV last week. “Then I just want to get through the qualifiers with the players who have got us through, knowing they are a year better on.

“I also want to just wait and see because I know the market in England and the rest of Europe well. I know how it works. It's later on in the window before players of real quality become available. I want to bring the best possible players into here.”

That is often true, that the best quality becomes available towards the end of the window, when selling clubs realise the need for compromise, but that’s not to say quality isn’t available earlier in the window.

Celtic were, for instance, able to lure Scott Sinclair before they’d secured Champions League qualification last summer. Moussa Dembélé was signed before the Champions League qualification had even been made.

New signing Hayes will provide Celtic with depth, offering them something different. But will he really make the difference at European level? Rodgers was backed significantly in his first season in Glasgow but Celtic must continue to back him. There’s still a long way to go.

While everyone at Celtic is geared for a tilt at the last 16 of the Champions League this season, with both Rodgers and majority shareholder Dermot Desmond admitting that to be the target as soon as the treble had been clinched, qualifying for the competition will still prove something of a challenge.

Indeed, having missed out on a seat at European football’s top table for two successive seasons before Rodgers’ appointment last summer, Celtic can’t get complacent in their assumption of Champions League qualification. It’s for this reason that their transfer market stance is something of a gamble.

Of course, those who pull the purse strings at Celtic Park would claim that it is the precise opposite of a gamble, instead living within the club’s means rather than splurging money they haven’t yet accounted for. But the cost of failing to make the Champions League group stage this season would be far greater.

Celtic have made this mistake before. Ronny Deila found himself in a similar situation upon taking over at the club in 2014, with only a handful of loan signings made before the Champions League qualifiers. The Hoops failed to make it through those qualifiers, with the failure to make it to European football’s premier club competition coming to define the Norwegian’s career in Scotland.

It seems unlikely Rodgers will suffer a similar fate. But Celtic are, nonetheless, taking a risk by refusing to allow him to significantly strengthen his squad before next month’s qualifiers. The Northern Irishman would surely wish to give his team the best chance possible of reaching the Champions League group stages, so this must be a decision from the top.

Celtic are a club heading in the right direction under Rodgers. Their aim of making the Champions League last 16 this season is an achievable one. But they must not underestimate how much of a challenge just qualifying for the competition remains. A difficult draw could put paid to those ambitions.

Celtic's summer transfer targets

From next season, the Scottish champions will face four rounds of qualifying before reaching the Champions League group stage. The task of simply pulling up a seat at the top table is getting more difficult with every passing year; Celtic must react to that.

Not so long ago Peter Lawwell and the Celtic hierarchy were the target of the fans’ frustration with a lack of investment seen to be the source of the club’s troubles.

The appointment of Rodgers, along with the signings made for him last summer, eased that frustration. But they must not make the mistake of thinking no more investment is needed. In fact, given their ambitions, investment is needed now more than ever.