Scotland head coach Gordon Strachan believes he made an error of judgement in accepting Saturday's friendly against Euro 2016 hosts France.
His side, who failed to qualify for the finals, which kick-off on Friday, were beaten 3-0 in Metz.
"I'm going to hold my hands up and admit I made a huge mistake in taking the team to France," said Strachan.
"All it did was give us a taste of what is about to come before having to walk away from it."
Strachan made the remarks in the first of a series of columns he is writing during the tournament in France for the Daily Record newspaper.
"I'm now struggling to work out what I was thinking when I took that game on," he said.
"I've got to take responsibility for that because I hoped our players would enjoy it.
"But, when faced with the reality of it, they just realised there's a huge event about to begin and we're not welcome at it.
"We saw the excitement of the people over there, the security - the whole enormous scale of the thing - and it made us feel even more miserable about ourselves.
"So that maybe wasn't the cleverest thing to do."
Prior to last week's 1-0 defeat by Italy, four days before facing the French, striker Steven Naismith had admitted that "it's not great to be the warm-up act" for other countries participating at the finals.
Strachan is now echoing that feeling and admits he is not relishing his scouting mission to watch World Cup qualification opponents England and Slovakia.
"I'll be in Bordeaux tomorrow to see Wales against Slovakia and I know I'll get betting all kinds of stick from the Welsh fans," he said.
"That's why I've already looked out my disguise. If anyone sees a Japanese navy admiral walking to the stadium, get out of his way and give the man a bit of peace.
"The truth is, the closer the kick-off gets, the more difficult it is for me to watch any of it.
"I'll nip in and watch the games and then nip out again because I am not going to enjoy any part of it."
'I can hardly stomach it'
It is the second major finals that Scotland will miss under Strachan.
He took charge in January 2013, after the departure of Craig Levein midway through the last World Cup qualification campaign, and his side finished fourth in their qualification group for Euro 2016.
"It won't feel anything like the last World Cup in Brazil, for example," he admitted.
"I went there as Scotland manager, too, but that was a campaign we knew we were never going to turn around.
"For that reason, it wasn't so painful to miss out. It was inevitable.
"But this time around? No, this time I can hardly stomach it."