The Belgium defender is set to miss the rest of the domestic season after limping out of City's Champions League semi-final defeat against Real Madrid on Wednesday with a groin injury.
Kompany, 30, lasted just six minutes of the tie in the Santiago Bernabeu before succumbing to the latest muscle problem in an injury-ravaged campaign. He ater released a message on his Facebook page that confirmed he will definitely miss the tournament.
"I'll miss the Euros," he wrote. "To me that's very sad news.
"So I could be standing here, feeling sorry for myself. I could fear for my career, as others may do. I could give up.
"That is not me. I decide on my future.
"There is a bigger picture to everything in life and only failing to see it, will cause me to fail.
"I am a hard worker and a fighter and if you are too, then you know that, to people like us, success can come in many forms. We trust ourselves when the going gets tough.
"I have the greatest respect for those who overcome their personal challenges in life with a positive attitude.
"I want to live up to that.
"So I remain calm and positive. I will continue to follow my path and I will do so with more conviction than ever.
"I trust my friends and teammates to do well and do us proud at the next European Championships in France. I am now officially their most fervent supporter and I will be there to support them.
"Written from my hospital bed,
"Never giving up,
The centre-half had flown back to Manchester with the rest of the City squad after the game, landing back in England just before 4am on Thursday.
But despite the late return, Kompany flew back out to Spain on Thursday afternoon in order to visit the practice of Dr Ramon Cugat in Barcelona.
Kompany was seen by Doctor Eduardo Mauri at the clinic in an effort to accelerate his recovery from the groin injury which could see him sidelined for six weeks and jeopardise his prospects of leading Belgium's Euro 2016 campaign.
Kompany will miss the remaining league games against Arsenal and Swansea City.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies