Juventus manager Massimiliano Allegri called Luis Suarez's Champions League-winning goal a "silly" one to concede after Barcelona's 3-1 triumph in Saturday's final.
The Bianconeri had equalised 10 minutes into the second half through Alvaro Morata, but Suarez put Barcelona back in front for good in the 68th minute.
Before the goal, Allegri's men had found a measure of control for the first time in the match, but Lionel Messi led a counter attack, firing a shot from the top of the 18-yard box that goalkeeper Gigi Buffon could only parry into Suarez's path.
"We had an extraordinary season, a great final and in our best moment of the game conceded a silly goal," Allegri told Sky Sport Italia.
"There were the chances to equalise, but Barcelona have three amazing players in attack and you have to take your opportunities."
He added: "It was incredible to concede that second goal in those circumstances against the run of play."
Juventus found themselves behind after just four minutes when Andres Iniesta slipped the ball to Ivan Rakitic to score the opener.
"We had trouble at the start finding our shape and the right channels," Allegri said. "We had several attempts, including the first of the game, and played well. In some situations we could've done better.
"At that moment we were pushing for the second goal and left ourselves open to concede on the counter from a goal kick.
Allegri also rued some missed opportunities to equalise late on, and hinted that Paul Pogba should have been given a penalty.
"We had numerous opportunities and luck wasn't on our side, as the deflection off a shoulder went over the bar, there was a push on Pogba, so we did have our say," the manager said.
The final scoreline flattered Barcelona has Neymar scored on another counter-attack with the final kick of the game.
"The goal for 3-1 was when the game was practically over," Allegri said. "I think it's another part of the growth process, as when you feel that the match is in hand, you need to be more careful."
Although the Treble slipped away at the final hurdle, Allegri praised his team for winning trophies in the Italian league and cup before turning his attention to next season.
"I think Juventus had a remarkable season with the Scudetto, Coppa Italia and reaching the Champions League final. What more could we have done?
"Now our task is to consolidate our position in the top eight of Europe, which in turn will make us even stronger in Serie A."