Dublin manager Anthony Daly says that Dean Curran 55th-minute sending-off proved costly for his side in their Allianz League Division 1A defeat to Waterford in Dungarvan yesterday.
Dublin bounced back from a nine-point deficit to cut the gap to four points. But defender Curran was shown a second yellow card by referee Diarmuid Kirwan 15 minutes from the end.
Daly feels that the sending-off had a huge bearing on the final result, which means the Dubs will face Galway in a relegation play-off.
"They were two of the most harmless things, and to be put off the field for it? Up to the sending-off, we were coming right back into the game and who knows what would have happened?" he said.
"That decision tends to turn the whole thing and they have a spare man there.
"We probably needed a goal but who is to say the goal wouldn't have come if we had had a three-man full-forward line, but that's ruled out when there is a guy sent off for very little, to say the least.
"We've performed against every other team bar Galway this year. They beat us by seven points, so our lads have all the incentive to prove they can compete with them and we'll look forward to that."
Meanwhile, Waterford boss Michael Ryan was happy his side had finished their league campaign on a winning note, stating that there was no crisis in the county.
"Everybody said it was a crisis but after three rounds of the league, Dublin hadn't won any game," he said.
"The National League champions haven't won any of their first five games, is that a crisis?
"It was a question of being patient - we've a new management team, we were without a lot of players early on and this was never going to happen overnight.
"The pressure was really on but they responded to it and we'd nine different starters (against Dublin) than against Cork. We struggled early on when we had a lot of injuries, but we didn't have a settled team and now we have."