The summer transfer window officially opened for business on Sunday and Celtic will be looking at ways that they can improve their squad ahead of the 2025/26 season.
Brendan Rodgers may have a domestic treble in his sights after his side ended this year with two of the three trophies, winning the Scottish Premiership and the League Cup.
The Northern Irish head coach will have at least one signing in the building by the start of next month, though, as Kieran Tierney is set to arrive from Arsenal on a free transfer when his contract at The Emirates expires.
With Greg Taylor out of contract and Jeffrey Schlupp’s loan deal expiring, the Scotland international is the only left-back on the club’s books heading into next season.
As well as wanting new signing to arrive to improve the team, Rodgers will also be hoping that some of the younger players in the squad can kick on and improve.
Hyun-jun Yang has shown plenty of promise during his two years at Parkhead so far, and his progression from year one to year two suggests that a big third season could be coming.
Why Hyun-jun Yang could be a star for Celtic
The South Korean attacker joined the Scottish giants from Gangwon on a permanent deal in the summer of 2023, and did not enjoy the best first year in Glasgow.
Yang ended the 2023/24 campaign with a return of one goal and three assists in 31 appearances in all competitions for the club, which shows that the winger provided little in the way of quality at the top end of the pitch.
This term, however, the 23-year-old star produced six goals and six assists in 34 matches for the Scottish Premiership champions in all competitions, whilst playing on the right and the left flank.
These statistics show that Yang has improved during his time at Parkhead, learning with more experience in Scottish football, and that is further illustrated by the difference in his performances in the top-flight.
Appearances
24
23
Goals
1
5
Conversion rate
5%
25%
Possession lost per game
9.8x
6.8x
Assists
3
2
Pass accuracy
81%
86%
As you can see in the table above, the South Korean star delivered more quality in front of goal and was more reliable in build-up play for Celtic, by being more efficient with the ball.
Gangwon president Kim Byung-ji claimed he “could easily become a world-class player like Son Heung-min” ahead of the winger’s move to Scotland, which illustrates how highly he is rated in his home country.
Yang is not at a world-class level, yet, but he is clearly improving, and Celtic are now reportedly interested in signing a player who could help to take his game to the next level in the future.
Celtic bid to sign English star
According to Football League World, Celtic have made an approach to sign Peterborough United left-back Harley Mills in the summer transfer window.
The report claims that the Hoops have tabled a bid to sign the 19-year-old defender from the English League One club, although it remains to be seen whether or not the Posh are willing to accept it.
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It adds that Premier League side Fulham have also made an offer of £1m for the impressive young full-back, which shows that there is set to be plenty of competition for his signature in the coming weeks.
Football League World adds that he would only join the Cottagers as an U23 player to bolster their academy, whilst the Hoops are looking for a player to compete with Tierney.
Meanwhile, Peterborough are also looking to pin the player down to a new contract, and it could be down to the player to decide which path is best for him moving forward.
If Celtic are able to win the race for Mills, though, then they could sign a left-back who could help Yang to fulfill his potential at Parkhead in the years to come.
Why Mills could be a great signing for Yang
At the age of 19, the Peterborough United star would arrive at Parkhead as a long-term signing who could grow into being the first-choice left-back for years to come.
This means that he and Yang could form a long-term partnership down the left flank if Rodgers opts to deploy the South Korean forward on the left wing, providing him with chances to cut inside onto his stronger foot instead of being forced down the line or backwards when on the right.
Mills only emerged as a regular starter for the Posh towards the end of the 2024/25 campaign, but his performances in the EFL Trophy and League One suggest that the potential is there for him to be an excellent option for Celtic.
The teenage star’s “stunning” free-kick at Wembley helped Peterborough to win the EFL Trophy in April, whilst he also averaged 3.2 tackles and interceptions per game across six appearances in the competition.
His form in League One, albeit only across 11 matches, also suggests that he could come in to offer more to the team from a defensive perspective than Taylor, who could leave on a free transfer this summer, did.
Appearances
28
11
Tackles per game
1.3
2.2
Interceptions per game
0.6
1.0
Clearances per game
1.9
2.5
Error led to shot or goal
2
0
Ground duel success rate
58%
65%
Aerial duel success rate
43%
57%
As you can see in the table above, Mills appears to be superior to the Scottish left-back across the board as an out-and-out defender, making more tackles, interceptions, and clearances per game, whilst also being stronger in his duels without making any big errors.
This suggests that the £1m-rated star could come in and lockdown the left-back position as a brilliant defender who could stop opposition wingers from pushing Celtic back in matches.
Not only could that improve the Hoops from a defensive perspective, but it could also free up Yang to play higher up the pitch on the left wing and closer to the opposition goal.
The South Korean star, if deployed on the left, would not have to track back as much if Celtic have a much better defensive full-back behind him instead of Taylor, potentially allowing him to be closer to goal to have more opportunities to score and create in the final third.
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This could, therefore, take his game to the next level and allow him to continue his upwards trajectory in a Hoops shirt, on his path to living up to the “world-class” claim.