Tyler Roberts feared his Euro 2020 dream was over after he was thrown out of the Wales squad in March for breaching Covid-19 protocols.
The Leeds striker was sent home along with Hal Robson-Kanu and Rabbi Matondo ahead of the 2022 World Cup qualifying win against the Czech Republic.
But, unlike his two team-mates, Roberts was named in Wales' 26-man squad for this summer's European Championships.
"I made a mistake and owned up to it," said the 22-year-old, capped 13 times.
"We've had conversations internally about it and it was good to chat with the gaffer (Robert Page).
Asked whether he feared for his Euros spot following his Covid-19 breach, Roberts Roberts - who apologised at the time for his actions - said: "Yes, definitely. It was obviously a mistake that I made and I was thinking straight away about the Euros.
"When you make a mistake it's a hard conversation to have. You have to be a man and own up to it.
"It was a learning curve and I'm just grateful not to have been in a worse situation.
"We've cleared the air and it's in the past, I'm looking to move on now and get my head down.
"I'm just grateful that I've been selected and the next thing is to make an impact and do well."
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Robson-Kanu, scorer of one of the greatest goals in Welsh football history when Chris Coleman's side beat Belgium in their Euro 2016 quarter-final, did not make the pre-Euros training camp in Portugal last week.
Schalke winger Matondo also failed to make Page's final party after travelling to Portugal.
"Rabbi was here, he was all okay," Roberts said. "He's disappointed not to be going but he's the type who will go back to his club, work hard and try and push to be in the next camp.
"When I found out I was in the squad it was an extremely proud moment. It was a very emotional time.
"I called my family straight away and let them know, it's been a great 24 hours."
Wales line up against Switzerland, Turkey and Italy in Group A at Euro 2020, with their opener in Baku against the Swiss on 12 June.
"Our ranking is quite high now compared to what it was," Roberts added.
"But I'd definitely say we are underdogs. That's great because we are confident we can go there and look to win."