Celtic will be going in search of the domestic treble in the 2025/26 campaign after they failed to secure all three Scottish trophies in the last two seasons.
Brendan Rodgers returned to Parkhead in the summer of 2023 and has won two domestic trophies in each of his first two terms back in Glasgow so far.
The Northern Irish head coach won the Scottish Premiership title and the SFA Cup in his second season, before losing to Aberdeen on penalties in the final of the SFA Cup.
Celtic also got through to the play-off stage of the Champions League, losing to Bayern Munich over two legs, and they may target more progress on the European stage.
The Hoops will need to be active in the summer transfer window in order to bolster their squad to kick on next season, and they already have one deal over the line.
Kieran Tierney will officially re-sign for the Premiership champions at the start of July after his contract with Premier League side Arsenal expires at the end of this month.
Why Kieran Tierney is an exciting signing
The Scotland international is an exciting addition for Rodgers and Celtic this summer because he is a proven performer who could come in and hit the ground running next term.
Tierney came up through the youth ranks at Paradise and made his breakthrough at first-team level with the Hoops before his big-money move to the Gunners back in 2019.
As you can see in the graphic above, the Scottish defender won five Premiership titles with the club and made the best part of 200 appearances before moving down south.
Six years on from his Parkhead exit, Tierney is now set to return to Glasgow and will provide Rodgers with a reliable option at left-back when fit and available, because he has been there and done it in the league and with Celtic, which is why this is an exciting deal.
However, there is also cause for concern with the 28-year-old star’s arrival this summer, because he has consistently suffered with injury problems throughout his career.
24/25
1
160
18
23/24
3
103
21
22/23
0
0
0
21/22
2
116
17
20/21
4
87
19
19/20
1
97
19
18/19
5
140
27
17/18
1
23
5
16/17
1
86
16
As you can see in the table above, the experienced ace has only missed fewer than 16 matches through injury in a season twice in the last nine campaigns for Celtic and Arsenal combined, which suggests that he is not likely to be available week-in-week out for the Hoops next term.
This means that the Scottish giants could need to bring in another left-back to play when the Bhoys academy graduate is unavailable, and the club have been linked with an interest in a teenage defender who could be an even more exciting signing than Tierney.
Celtic's interest in teenage full-back
At the end of last month, Sponichi Soccer, as relayed by The National, reported that Celtic are one of a number of teams interested in a deal to sign Djurgardens left-back Keita Kosugi in the summer transfer window.
The outlet claimed that Champions League winners Paris Saint-Germain and Italian side Atalanta are also eyeing up a swoop for the 19-year-old defender, as they look to bolster the depth in their respective squads.
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It did not reveal, however, how much money it would take to convince the Swedish side to part ways with their impressive Japanese left-back this summer, so it remains to be seen how much the Hoops would have to pay for his services.
The interest from PSG and Atalanta does show, though, that Celtic could find it difficult to get a deal done for the defender because they would have to convince him to turn down the chance to play in one of Europe’s major leagues.
It is now down to the club to press ahead with a swoop for the Djurgardens star, because he could be an even more exciting signing than Tierney this summer.
Why Kosugi would be more exciting than Tierney for Celtic
Whilst the Scotland international is a proven Premiership performer who could come in to make an instant impact as a known quantity for Celtic, he represents the past more than he does the future.
Tierney, although he still has some years ahead of him at the age of 28, has shown that he cannot be consistently available due to his constant injury problems, which means that the club may not be able to rely on him moving forward as a go-to option every week.
Kosugi, meanwhile, is 19 and has the majority of his career ahead of him and could go on to be Celtic’s first-choice left-back for many, many, years to come.
He has also yet to suffer a significant injury in his career, with no injury absences listed on Transfermarkt, which suggests that the youngster is more likely to be available week-in-week-out in comparison to Tierney.
Kosugi, who was dubbed “impressive” by video scout Elijah Michiels, also showcased his quality in the Conference League for the Swedish club in the 2024/25 campaign, as shown in the clips above.
Appearances
12
11
Goals
0
2
Key passes per game
1.3
0.9
Big chances created
1
5
Tackles + interceptions per game
3.2
3.2
Clearances per game
3.5
3.5
Duel success rate
50%
53%
The 19-year-old defender, as shown in the statistics above, is a full-back who has shown that he can combine offensive output with defensive strength, particularly in Europe.
Kosugi, who was described as a “standout” in the Conference League by Jacek Kulig, can provide goals and creativity whilst also making plenty of tackles, interceptions, and clearances each match.
Meanwhile, Tierney averaged 0.7 tackles and interceptions per game and created two ‘big chances’ in 13 appearances in the Premier League for Arsenal this season.
Overall, Kosugi could be a more exciting signing than the Scottish defender because of his potential to play week-in-week-out, coupled with his age profile and his superior performances in comparison to Tierney during the 2024/25 campaign.
Celtic could sign Matt O'Riley 2.0 in swoop for "unplayable" star
Celtic could repeat their Matt O’Riley masterclass by swooping to sign this star.
ByDan EmeryJun 5, 2025
That is why the board must push to win the race for the 19-year-old starlet’s signature ahead of PSG and Atalanta, as difficult as that may seem, this summer.
