Getting Brendan Rodgers back was never going to come cheap.

However, it appears Celtic are ready to deliver a transfer budget to match a stellar managerial appointment. It’s reported the Premiership champions could spend as much as £30m on new signings this summer, an unprecedented figure in Scottish football.

It’s believed Rodgers’ return to Parkhead was facilitated in no small part by assurances the club would back his vision to make Celtic a competitive European side once more. Such an ambition requires significant investment if Rodgers is to mould a team capable of consistently taking on the continent’s very best.

Domestically, the squad assembled by Ange Postecoglou was near-flawless – so just how do you improve upon it? Let’s take a look across the pitch at where Rodgers could look to level up.

Goalkeeper

Joe Hart was a shrewd acquisition by Postecoglou, bringing reliability and personality to a Celtic side which had very much lacked those qualities between the sticks since Fraser Forster decided he would rather remain in England. But with the former Manchester City and England keeper now 36, there will likely be some succession planning under way.

A key reason he fell out of the Etihad picture when Pep Guardiola arrived in 2016 was the manager’s desire for a goalkeeper more adept at dealing with the ball at his feet. Hart is perhaps from the last generation of keepers for whom being actively involved in build-up was not a crucial requirement of their skillset, but the game has moved on markedly and this has never been an area in which he has truly excelled.

Given Rodgers’ widely reported European ambitions, it feels likely he could look for a younger number one who could hold the jersey for several years to come.

Defence

Rodgers will not be able to call upon Cameron Carter-Vickers until late summer as the US international recovers from knee surgery. But his absence will, at least, give the new manager an opportunity to assess the alternatives.

Carl Starfelt has been ever-present beside the former Tottenham academy graduate, but for the final games of the season he was partnered alternately with Tomoki Iwata and Yuki Kobayashi. Iwata had been used primarily in midfield by Postecoglou until then, and Kobayashi looked as though he still has much adaptation to do in getting to grips with Scottish football.

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Stephen Welsh barely got a look-in last season and could depart over the summer. With Celtic set to compete on four fronts at home and in Europe next season, Rodgers may feel more comfortable heading into the campaign with an extra option at the heart of defence.

The new manager has already been linked with his former Leicester City centre-back Daniel Amartey. The 28-year-old Ghanaian is out contract at the end of this month but would still command a hefty wage packet. Bringing in a player with his level of Premier League experience would be an early statement of intent.

Midfield

Celtic have an embarrassment of riches in the middle of the park these days but it’s not out of the question that at least one of those top talents could be in line for a big summer transfer. Reo Hatate has been linked with Brighton & Hove Albion, who have already sold Alexis Mac Allister to Liverpool and look set to lose Moises Caicedo, too.

The Japanese midfielder clearly has a high ceiling, albeit has stated he is no rush to depart Glasgow when there’s another Champions League campaign just around the corner. Postecoglou had made no secret of his desire for Celtic to be consistently ‘aggressive’ in the transfer market, a principle he applied to selling at the right time, as well as moving efficiently to bring players in.

There was a feeling Hatate may be next in line for a big move, but there’s always the chance Rodgers will see things differently. He worked wonders with Celtic’s midfielders during his first spell, reviving Scott Brown’s career, turning Stuart Armstrong into a key player as well as elevating Callum McGregor and Tom Rogic to another level. It would be no surprise if he sought to hang on to Hatate at all costs, reasoning that signing a replacement of the same or better quality would eat considerably into his budget.

Rodgers has been linked with a highly ambitious move for another of his former Leicester players in Wilfrid Ndidi, but he is likely to command a fee in excess of what Celtic can realistically spend, as well as earning money well outside their wage structure. At the very least, though, it could be a clue that midfield targets are on Rodgers’ radar.

Attack

Another area of the pitch where Celtic are not short on options, yet it seems a safe bet Rodgers will still look to make additions. What happens at centre-forward will largely hinge on if any move is made for Kyogo Furuhashi.

Postecoglou is reportedly interested in taking the striker to North London, but if Celtic resist those advances with the same vigour they displayed when Ange came calling for John Kennedy and Gavin Strachan, it’ll be a tough ask to prise Kyogo away from Glasgow.

The Japan international’s contribution to Celtic’s domestic success last season cannot be overstated. Time and again it was Kyogo who found a way past a stubborn Premiership defence, and he is the epitome of Celtic’s knack for just getting the job done in the league week after week. His contribution in Europe was not as telling, as a lack of ruthlessness in front goal came to partly define a Champions League tilt in which no victories were recorded.

Kyogo wasn’t the only offender in that regard, but Celtic will need someone who can score at the very highest level if Rodgers’ continental ambitions are to be realised. Whether he feels Kyogo can be that man, or an upgrade is required for Europe remains to be seen.

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On the flanks, Rodgers again has plenty options. Jota and Daizen Maeda were Postecoglou’s first picks last season, but how the latter will fit into the new manager’s plans is especially intriguing. Maeda’s pace and work-rate are astonishing, but fans did feel frustrated on occasion by a technical ability that is not quite on par with his Portuguese team-mate. Rodgers demanded goals from his wingers when he was here last, and got plenty from James Forrest and Scott Sinclair.

He will be aware of Liel Abada’s prowess in finding the net, and if the Israeli remains in Glasgow he could take on a more prominent role having found himself flitting in and out of last season’s starting XI. But with Forrest’s advancing years, uncertainty around the returning Mikey Johnston, and Sead Haksabanovic’s inconsistent debut season, Rodgers could look for new faces on the flanks.