Are Celtic ready for fight on all fronts?

With Celtic about to begin the defence of their Scottish title and facing a crunch Champions League qualifying play-off, just how equipped are they to build on recent success and progress again this season?

Recruitment, aligned to key departures, has been a central theme of Celtic supporter conversation of late, with apparent concern that the squad is lacking in a number of areas that was echoed by manager Brendan Rodgers saying on Friday that there are "gaps in the squad that are very clear".

There is still a long way to go in the transfer window, but with the expectation of a stronger title challenge from Rangers and a clear desire for continued participation at European football's top table, are Celtic ready to take on the immediate challenges ahead?

Rodgers targeted improvement in Europe as a key aim on his return to the club and got that last season, pushing Bayern Munich in the Champions League play-off stage to narrowly miss out on a last 16 spot.

Participation on that stage this season will be determined by a play-off in just under a month and missing out would be a significant setback.

With just one year left on Rodgers' three-year contract, what happens over the coming weeks may go a long way to determining if he believes he can continue such progression.

Indeed, despite saying he is "very happy" at Celtic, the 52-year-old Northern Irishman stressed he is "not the type of manager" to stick around if a club is merely treading water and that there was "no update" on a new contract.

With Rodgers entering a third season in charge of Celtic for the second time, it has been almost undiluted domestic success across both spells.

Two domestic trebles in his first two seasons came alongside challenging Champions League campaigns.

League Cup victory in 2018 meant a seventh straight domestic trophy, but a perceived frustration that he had hit a ceiling with Celtic and the lure of the English Premier League sparked fury among a previously adoring support as Rodgers left for Leicester City.

His return four years later was met with a lukewarm response. He stated he would be there for the full three-year contract and quickly started winning trophies again to win over the support.

He has won two league and cup doubles in two seasons, but it is the clear improvement at Champions League level that showcases Celtic's progression under Rodgers.

For that to continue, he has repeatedly stressed the need for quality additions to his squad.

That need has become acute with the exit of Nicolas Khun, the long-term injury to fellow winger Jota and the lack of a direct replacement for Kyogo Furuhashi since the Japan forward left in January.

The question is whether Celtic's recruitment ambitions match Rodgers' desire to continue driving the club forward and what that means moving forwards?

Rodgers has repeatedly used the word "quality" when describing what his squad needs. He's also been clear that he wants more firepower and is short on natural wingers.

Scotland defender Kieran Tierney's return adds undoubted talent and Sweden winger Benjamin Nygren appears to be good business on early evidence.

Other new faces appear to be mainly for development.

What is clear is a significant section of the Celtic support feel a reluctance to spend significant sums is putting not only European ambitions at risk but also their domestic dominance.

Is that fair?

FThe former Celtic midfielder Scott Allan understands fan frustration but points to the return of Tierney on a free transfer as an example that is being somewhat overlooked.

"The fact that they were able to get Tierney on the free papers over the fact that he's a player of immense quality," he told BBC Scotland.

"The only concerning thing is the fact that Brendan Rodgers actually spoke about players coming in and not necessarily getting in as starters.

"I think Celtic fans are looking at players who can come in and affect the team now and that's where the concern is growing from."

Celtic's long-term transfer strategy has delivered time and time again and must be the envy of many clubs.

Huge profit has been brought in for the likes of Matt O'Riley, Jota and Kuhn.

Celtic spent big last summer on midfielder Arne Engels and striker Adam Idah. With hindsight, some fans feel they may have overpaid, but that view may change over the coming months.

A rough estimate of receipts this summer alone suggests a figure of around £20-25m has come in against a spend a fraction of that.

A reminder of the first window of Rodgers' second spell is notable in terms of fan satisfaction. Celtic recruited widely and supporter reaction at the time seemed overwhelmingly positive.

A look through that list of names might provide some caution. Luis Palma, Gustaf Lagerbielke, Kwon Hyeok-kyu, Marco Tilio, Odin Thiago Holm and Maik Nawrocki have all failed to make the grade after an outlay of close to £15m.

Caution and care over fees may bear more fruit than the examples above.

Rodgers has repeatedly indicated that he expects his squad to be stronger come the end of August and there is likely to be movement in the coming days and weeks.

The question is whether that will be enough to satisfy him and a support desperate to enjoy continued domestic success and see their team build on a successful Champions League campaign last term, with that play-off hurdle crucial.

"I can totally understand his Rodgers' frustration," Allan said.

"He spoke after the Bayern Munich exit about evolving every year. That was probably looking ahead to this window.

"There were a lot of questions asked when Kyogo left. Daizen Maeda did a job as number nine, but I think there's no question Brendan Rodgers prefers him on the wing.

"He's wanting to evolve the team, he's wanting to go longer in Europe and that comes down to getting quality in."

In Rodgers' own words, Celtic have work to do in this window with significant challenges coming over the horizon.