Japan manager Hajime Moriyasu admitted it was "really painful" to snub Celtic hero Kyogo Furuhashi for this month's Asian Cup.
The Hoops ace was a shock omission for their squad for the tournament, with Parkhead teammates Reo Hatate and Daizen Maeda both included.
Kyogo also suffered heartache after he was not called up for the World Cup in Qatar, but was recalled by Moriyasu and won the last of his 21 caps so far against Myanmar in November before not making the final cut for the Qatar event.
Japan warmed up for the tournament with a 6-1 win against Jordan and will face Vietnam, Iraq and Indonesia in the group stages.
And asked directly about why Kyogo wasn't in the squad in an interview in his homeland, boss Moriyasu admitted it was a tough decision.
He said: "It was extremely difficult. It's just really painful to make decisions like these.
"On the one hand, as manager of Japan. I am delighted we have such a deep squad depth and we could probably pick two or three teams who could compete competitively on the world stage.
"And that will only increase as we have a lot of good, young players coming through.
"But it makes my job very, very hard. Regarding the criteria for this tournament, I went for the ones I thought had the most individual strength.
"I wanted players who can overcome situations individually and have to have the ability to connect with people and work together with those around them.
"We picked players who can improve their abilities not only by themselves, but also by working with their team-mates."