David Turnbull, Aaron Mooy and Celtic's complex contracts situation

Celtic's recent transfer business and agile squad management have meant that the club sit in a healthy position in terms of contracts.

Ange Postecoglou - along with chief executive Michael Nicholson and head of recruitment Mark Lawwell - have transformed the way the Scottish champions are operating in the transfer market.

It seems like the days of multiple loan signings and talents being allowed to run down their deals are a thing of the past.

They have also made sure that marquee acquisitions such as Cameron Carter-Vickers and Jota are signed up to long-term deals as another layer of security for the club.

However, there are still a few squad members whose contract situations need to be cleared up.

David Turnbull's deal expires in the summer of 2024. The midfielder has played 6,833 minutes for Celtic since joining ahead of the ill-fated 2020-21 campaign and in that time - which is the equivalent of around 75 full 90s - he has netted 24 goals and laid on 16 assists.

Given he has spent a significant portion of time out with injury at stages, it is a decent return in terms of goal involvement. 

The 23-year-old was a regular starter when Postecoglou first arrived and played a significant role during the first part of last season before a hamstring issue suffered in the League Cup final against Hibernian kept him out for a few months.

READ MORE: How cold-blooded Celtic finishing left St Johnstone shaken

This season, with the addition of Aaron Mooy along with Reo Hatate and Matt O'Riley becoming established players in the squad, the former Motherwell man has found his game-time limited.

Turnbull has five goals and five assists overall this season which, given he has only played 1,093 competitive minutes, is an impressive return. That said, 20 of his 28 appearances this season have come from the bench but he has made an impact with seven of his 10 goal contributions coming as a sub. 

With just over a year left on his deal, it makes sense that the Hoops do everything they can to keep him if possible.

There is, of course, another reason beyond pure performances that makes keeping Turnbull around a sensible move: Europe. The midfielder is a product of Motherwell's youth system and as such counts as a nation-trained homegrown player for Celtic's Champions League squad registration list.

In front of Turnbull in the pecking order for the time being, Mooy is quite simply the man of the moment at Parkhead. With goals, assists and a catchy song, the 32-year-old has it all.

It is fair to say he has already surpassed most expectations since arriving in the east end of Glasgow. The midfielder joined on a free transfer, having left Chinese Super League side Shanghai Port, in what the club announced as a two-year deal despite reports at the time suggesting it was one season with a year's option included.

Whether it's 2024 or 2025, the way Mooy is playing right now puts him right there as one of the first names on the teamsheet so perhaps extension chat is a no-brainer. However, his age and his relatively recent emergence as a first-XI challenger means the club does not need to move urgently in terms of a new deal.

Make no mistake, though, it is something that will be considered come the summer or early next season if this version of Mooy continues to perform unabated.

On the subject of first-XI challengers, Joe Hart is in a peculiar position. The Englishman has revitalised his career in Glasgow since arriving from Tottenham in the summer of 2021.

A key part of the double-winning team during Postecoglou's maiden season in charge of the Hoops, the 35-year-old brought much-needed stability to a position that had lacked it since Fraser Forster chose not to return to the club.

He is the undisputed number-one goalkeeper, having played more minutes this season than any other player. Yet while he has still been solid enough this season, limitations in his game have also become more apparent.

His distribution has been sloppy at times - think away to RB Leipzig in the Champions League or in the recent derby against Rangers - and while the former Manchester City man is still a capable shot-stopper he has struggled more in his second season with that as well.

According to StatsBomb, Hart has conceded the fewest goals in the league so far this season but is fourth for goals saved above average (GSAA), a metric that reflects how many goals a keeper's saves have prevented within a season in context of the shots they have faced. Kelle Roos of Aberdeen and Hearts shot-stoppers Craig Gordon and Zander Clark are all ahead of Hart on that front.

Ultimately it comes back to the question of ambition. If the Hoops want to truly progress in Europe then, in the long-term, a goalkeeper who is better with the ball at his feet will be required.

Hart's contract is up in 2024 so, like with Mooy, there is no real rush to ponder an extension or not at this juncture - but it very much is a discussion that will have to be had further down the line.

READ MORE: How much has Ange Postecoglou improved Celtic this season?

In terms of his successor, it's unlikely they are already at the club. Conor Hazard's deal expires this summer and it is expected that, unless there is a drastic change of circumstances, he will depart Parkhead. Scott Bain seems content with not playing and will either leave this summer or in 2024 when his contract expires.

Benjamin Siegrist, meanwhile, is likely to be the number two when he returns from injury given he has featured twice this season and is contracted until 2026. Highly-rated youngster Tobi Oluwayemi is currently on loan at Irish side Cork City and will be looking to challenge for a first-team squad place when he returns.

Of course, it is important to remember that while contract lengths can provide security they can also cause issues.

James McCarthy, for example, will still have two seasons left on his deal come the next transfer window but, given he has only played 62 minutes this season, is surely someone the club should get off its wage bill much sooner than that.

Yosuke Ideguchi falls into a similar boat. With a contract running until 2026 and having not played any competitive football during the current campaign, this summer seems the ideal time for the Japanese midfielder to leave.

Even further down the pecking order, you have the likes of Albian Ajeti, Vasilis Barkas and Ismaila Soro. All three have deals until summer 2024 so the next transfer window will likely be earmarked as the best - and possibly the last - chance for the club to make any real money back on them.

While it is certainly accurate to say this Celtic squad is in rude health, making decisive calls on the likes of Hart and Turnbull as well as moving on some of the deadwood where possible as summer approaches can ensure it remains robust for some time to come.

This piece is an extract from the latest Celtic Digest newsletter, which is emailed out every weekday evening with a round-up of the day's top stories and exclusive analysis from The Celtic Way team. 

To receive our full, free newsletter including this analysis straight to your email inbox the day BEFORE it appears on the website, click here and tick the box for The Celtic Digest