Barca won 3-0 via goals from Ferran Torres, Dani Olmo (penalty) and Robert Lewandowski.
Moreno said afterwards: "There were a couple of plays where we found openings, but we were offside. We had a few chances, and if you want to get something positive, you have to get them right. Barça played a great game, and we didn't."
However, Moreno insisted the second half wasn't bad, and when "the team was at its best, the third goal came".
Everything came down to the second goal for Barça, thanks to a Dani Olmo penalty. The penalty was retaken for Jon Moncayola's penalty area encroachment.
Moreno was blunt: "The penalty retake was a good thing, the penalty was not."
Osasuna now has 12 points in the last 15 matches. The solution, according to Moreno, is "to stay calm, focus on the next game, and not think about today's. It's no consolation, but Barça scores a lot of goals on average, and they haven't conceded as much as other teams."
Neither Barça nor Osasuna wanted to play on Thursday night.
Regarding this controversy, Moreno added: "We had asked not to play the match today, but they didn't listen to us. It seems we don't have international players, nor do we play this weekend. We'll look to Athletic to try and win."