Speaking to the Official Club Website, Keane said: "We made a sluggish start and the first goal was always going to be important.
"We had some decent chances and we're disappointed we didn't hit the target. Their 'keeper made a good save from Gareth [McAuley] and yet again it shows that we don't score enough goals.
"When you make a mistake like we did for their first goal, then you put yourself under pressure. We made it difficult for ourselves and then we gifted them a second goal and it's a long way back from there.
"We didn't do enough to win the game and it's left me frustrated more than angry because we have been here before. We are taking one step forward and two steps back."