Portugal kicked off their campaign with a heavy 4-0 defeat to Group G winners Germany, and Nani believes that their exit can be traced back to that loss in Salvador.
"We knew that it would be hard to qualify for the next round. We needed five goals and that proved to be too much," Nani told Goal.com.
"We got a lot of chances to score, but we got only two goals in the end. We have to accept that we're out and move on.
"I think we deserved to progress, but those four goals we conceded against Germany cost us. We were determined to turn things around against Ghana, but it was not enough."