Juventus coach Andrea Pirlo admitted frustration after their Champions League defeat to Porto.
Juve lost 2-1 in the first-leg of their round of 16 tie.
“When you concede a goal after one minute, a strange one at that, it's natural the players will lose confidence, especially against a side that knows how to clam up in defence," Pirlo told Sky Italia.
“Porto got the game immediately on the track they wanted. With such a packed fixture list, it's normal you can't always maintain absolute focus and the right tempo, but it shouldn't have happened in the Round of 16 of the Champions League."
Federico Chiesa gave them some hope with a late away goal, while Cristiano Ronaldo had penalty appeals rejected in stoppages for the Zaidu challenge.
Pirlo also admitted: “We moved the ball around too slowly and weren't intelligent enough to realise the dynamics of the game we were going into.
“The intention was to spread the play, but we didn't do it enough in the first half, a bit more towards the end. It's not easy against a team with 11 men behind the ball.
“We had prepared well for this game, it was not the attitude we wanted, but conceding a goal in the opening minute when we handed it to them on a silver platter made everything more difficult."
