Manchester United's £7m left-back prospect looks bleak, waiting a year without a debut! Carrick wants to sign a new left-back.

Last summer, 18-year-old Paraguayan Diego Leon traveled to Manchester, confidently declaring at his home airport, "I will make a big impression in pre-season and, with just one or two matches, I'll blend into the first team and compete alongside them."

But after a full season, Leon's prediction fell short. In the final home pre-season match, he appeared alongside Cunha, Mbeumo, and Sesko, but unfortunately, he then had to return to youth-team games. Many fans even forgot the club had signed this player, despite his total transfer fee reaching £7 million.

In the first few months after his transfer, Leon performed quite well, leaving a strong impression at Carrington. Before the pre-season friendly against Leeds United, he was given a first-team squad number—initially No. 30, later changed to No. 35 due to Sesko's arrival.

Former Manchester United manager Ruben Amorim started Leon in the first friendly. Later, in the US matches against West Ham United and Bournemouth, Leon came on as a substitute. When the season officially began, he was named in the first-team squad for the League Cup tie against Grimsby, but United suffered a shock elimination, costing him the ideal chance for his debut.

If the Red Devils had been leading by a large margin against the League Two side, Leon would definitely have been brought on. Unfortunately, United fell behind 0-2 at one point and eventually lost on penalties, so the Paraguayan left-back missed his debut. Between September and October, Leon was repeatedly named on the bench for matches against Manchester City, Brentford, and Sunderland, among others. Yet he never got any playing time.

According to the Manchester Evening News, United's coaching staff concluded that Leon still has much to learn and improve, so they believed he needed to return to the youth team for development. His final match of the season was against Brighton, but not in the Premier League's final round for the first team; instead, it was the Premier League 2 play-off final. Leon played for United's U21s, and the team lost, missing out on the title.

A week later, Manchester United's first team also visited Brighton, where Dutch left-back Tyrell Malacia was given playing time as a farewell appearance before his departure. Leon did not make the squad; Carrick only selected two academy youngsters, Shea Lacey and Tyler Fletcher.

British media revealed that Carrick chose Malacia to recognize his professional attitude over the past season. However, if Leon had performed better in youth-team matches, he could have replaced the 26-year-old Dutchman and stepped onto the Premier League stage.

Malacia made just two appearances for Manchester United this season, with unremarkable performances, and he was the culprit in the late defeat to Newcastle United. Yet Leon's performances were clearly considered even worse than his.

When Manchester United signed Leon from Cerro Porteño in Paraguay, they paid an initial transfer fee of £3.3 million, with various add-ons potentially bringing the total to £7 million. United valued Leon's potential and believed he could eventually establish himself in the first team. However, if he wants to fulfill his talent and earn opportunities, he must work hard to improve himself.

Leon is already 19, an age at which many Premier League left-backs have already made a name for themselves. For instance, Arsenal's Myles Lewis-Skelly, an English player reportedly targeted by United, is also 19, while Newcastle's Lewis Hall and West Ham's Haji Diouf are only 21. All three are left-back targets that United are rumored to be pursuing. Leon has reached an age where he needs to meet higher standards at United, and next season will be a decisive moment for him.

If Leon performs well in pre-season, he could have a chance to return to the first team next season. However, according to the Manchester Evening News, based on his performances this past season, his chances of success are slim. Although he showed some bright spots, such as a half-field solo goal against Tottenham, his overall technique is still immature and not up to the demands of the first team.

Coming from South American football, Leon has not yet adapted to the English football environment. In a match against Liverpool last September, he was even substituted at half-time by United's U21s. Carrick's coaching staff includes former United reserve team head coach Travis Binnion, so their judgment on young players is well-founded.

Regarding Leon, Binnion once commented: "Everyone can see that he has talent and a solid foundation, which are advantages for future development. But he understands, and we know, that there are many areas he still needs to improve. First of all, he must be able to play 90 consecutive minutes."

Manchester United once hoped to loan out Leon in January, but he and his agent Renato Bitar stated that Leon was still in the process of familiarizing himself with the club, and sending him away at that stage was not ideal. However, if a suitable club can be found, Leon might need to consider a loan move for the new season to gain experience.

After joining Manchester United, as the first Paraguayan player in the club's history, Leon was called up to his national team for the first time and made his debut. However, he is unlikely to make the World Cup squad and will need to stay at the Red Devils to continue proving himself.