Shin Yamada has made it clear his full attention is on Japan duty, even as a move to Celtic edges closer with a £1.5 million deal reportedly nearing completion.

The Kawasaki Frontale striker has been honest about his form this season, expressing disappointment with his domestic output before turning his focus to the international stage.

Celtic look poised to add the 25-year-old to their growing Japanese contingent, with the player expected to head to Glasgow once Japan’s EAFF E-1 Football Championship campaign wraps up. Their final match in the tournament is against South Korea next week.

Yamada made his senior international debut in the 6-1 win over Hong Kong, coming off the bench in front of a small crowd of just 687 spectators in Yongin.

While pleased to earn his first cap in a squad made up entirely of J.League-based players, the forward acknowledged his struggles at club level this year, scoring only twice in 21 appearances after hitting 19 goals last season.

He said: (RecordSport), “I went into the game with the feeling that this was my chance to impress and although we won, I thought I could have done more.

“I think that going forward, when we compete in the World Cup, it will be against far more difficult opponents, so I need to keep that in mind as I work on my national team progress.

“I thought I might have been able to score a goal, but I think I learned a lot from this. On a personal note, I have to admit I have had a disappointing season.

“I set high standards for myself and I don’t think I met them if I am being honest. Yes, I enjoyed a very good season previously and scored a lot of goals, but for whatever reason it didn’t happen again this season.

“I think the team played in a different style and that made a difference, but I am fully aware I have to raise my standards.”

Yamada’s honesty will be noticed by Celtic supporters who are hopeful he can follow the path of Kyogo and Daizen Maeda, two Japanese forwards who made an immediate impact in Glasgow.

His poor run of form might cause concern, but his ability to speak openly about his struggles shows a strong attitude as he looks ahead to a possible move to the demands of playing at the Hoops.

Celtic are already well into their pre-season schedule, and Brendan Rodgers will want Yamada to be sharp and ready if the transfer is completed. Playing in competitive matches for Japan could help him slot in quickly if he joins up with the squad later this month.

He’ll have one last chance to show what he can do in the final game against South Korea before the move is expected to be confirmed, with Celtic still looking to strengthen before the new season kicks off.