Posh recovered from a poor first-half to take a 2-1 lead just past the hour mark before conceding twice in the final 20 minutes to make it 15 Championship games without a win.
McCann’s men remain bottom and seven points from safety with just nine games to go. The boss blamed a sluggish start to the match and then poor game management late on for the latest loss. He said his side ‘crumbled’ after taking the lead.
“In the first half we didn’t get against the ball enough,” McCann said. “We knew what Swansea would do and we had a plan for it, but we didn’t execute it at all well. We didn’t press at the right times. We sat off them and let them dictate the game. At times we had a back seven or eight and we needed players to push other forward.
“We changed a couple of things and played on the front foot at the start of the second-half and we started to cause them problems. We managed to get in front and then it was just a question of managing the game, but instead we just sat back in our shape and let them dominate the final 20 minutes.
“I can’t fault the effort from a really good set of lads, but what upset me the most was how we crumbled in the final 20 minutes. If you let good, experienced Championship players have the ball they will punish you and that’s exactly what happened.
“We conceded a goal after losing possession on the halfway line which should never happen, I don’t mind losing possession as that happens to every team, but it’s how you react that’s important.
“I was worried at half-time because the changing room was so quiet. They are really good lads who are doing their best for the club, but you could hear a pin drop. I’ve never known a changing room so quiet. It can’t all be about me and Cliff (assistant manager, Cliff Byrne) having a pop. Sometimes you need the changing room to manage things. That has to change and it will.
“It’s a bitter pill to swallow tonight. There were some positives - Ricky-Jade Jones was sensational and we missed him when he went off - and I have seen things I have liked and some things I haven’t liked, but we will refocus for the next game and see if we can get better.
“People will look at the table and see the seven point gap and thinks that it’s all over, but we will keep plugging away.”
Posh are next in action at QPR on Sunday (March 20, 12.30pm).