"You don't expect the players we have got to concede goals but they are and they take a big responsibility for what happened today.
"Obviously we have lost the game and we didn't do as well as we should have, but we certainly didn't deserve that.
"Moments in the game were decisive; Portsmouth took their chances well and I didn't think we took ours."
Moyes also admitted that Yakubu's penalty could have been better.
"It was a poor penalty, no doubting that - but it was a good save as well.
"People can miss them and you have got to be brave enough to take them. I thought Yak was going to score when he went up to take it."