'If in a match against players like they (Morocco) have, if you don't have the ball, they will wear you down and you get into trouble.'
Portugal inexplicably lost control of the game despite managing to beat Morocco 1-0 in the World Cup Group B match on Wednesday and were lucky not to get themselves in more trouble, coach Fernando Santos said.
The European champions took the lead in the fourth minute when Cristiano Ronaldo charged into the box to bury his header and become Europe's top international scorer with 85 goals.
But they instantly eased off and offered little else in terms of attacking football for the rest of the match.
Instead it was Morocco, who lost their Group B opener 1-0 to Iran, who were the more aggressive side, missing half a dozen clear scoring chances and the Portuguese conceding far too much space.
"We have to look at this and we have to talk about it," Portugal coach Santos said.
"We lost control of the game, we misplaced a lot of passes, we lost confidence.
"It was inexplicable. If in a match against players like they have, if you don't have the ball, they will wear you down and you get into trouble."
Goalkeeper Rui Patricio was kept busy by the North Africans and helped Portugal earn the three points and move top of the group on four.
Iran have three points and Spain one ahead of their meeting later on Wednesday.
Morocco failed to convert their chances and are pointless and cannot progress to the second round.
"Of course, no World Cup match is easy even against teams that are theoretically weaker," said Portugal defender Jose Fonte.
"Today, again it was the same situation. They are a team which caused a lot of trouble. We knew how to suffer."