Russell Martin says Swansea City were the creators of their own downfall as they were beaten 3-2 in their FA Cup third-round clash with Southampton.
The Swans came from behind to take the lead in extra time before conceding twice as they lost for the fourth game running.
Head coach Martin bemoaned his side's mentality after they went 2-1 early on in the first half of extra time at the Swansea.com Stadium.
"After conceding I thought the nerves went, and the attitude was one of 'we've got to click into gear at some point or this could be a long afternoon'," he said.
"After that I liked loads of it. It's just a case of trying to break them down and play with real intensity and patience.
"They have two shots on target in the whole 90 minutes. We score the goal, Joel Piroe has an unbelievable chance to finish it off, Fraser Forster makes a great save, and then in extra time we score and the mentality is... I think they think the game is done.
"We're playing against a team who bring three fresh players on at the top end of the pitch. It hurts because of the lack of the right mentality to dig in, protect the lead, and go and play in the same way.
"We've plotted our own downfall really, today. There were some outstanding individual performances.
"I feel like we know where we're at. We haven't learned anything new today. We have some outstanding people who are growing every week, we have some players not involved very much and we have some areas where we really need to improve and strengthen.
"So I'm really hurt in the way we lost the game, I said to the guys it's not acceptable to do that.
"It's the mentality after we score, the guys think it's done."
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Nathan Redmond gave Southampton the lead after just eight minutes, although the Saints had Yan Valery sent off on the half-hour mark.
Joel Piroe notched his 13th goal of the campaign to send the contest into extra time before Olivier Ntcham's strike deflected in off Jan Bednarek.
But Mohamed Elyounoussi and Shane Long both struck shortly after the Swans had gone ahead as Martin's men lost their first game of 2022.
Swansea's focus now switches to bolstering their squad in the January transfer market having already seen Ethan Laird and Morgan Whittaker leave the club.
And Swans boss Martin said he was hopeful that Swansea would be active in the winter window prior to their Championship clash with Huddersfield Town next weekend.
"I would have thought so. It's really difficult, I can't promise anything," added Martin when asked if he would add to his squad before next weekend.
"January, it changes very quickly, the landscape. As it stands, how far down the line we are with a couple, we're hopeful, but that's all we ever are.
"Nothing is nailed on until it's done in football so we'll have to wait and see."
The Swans take on Huddersfield next Saturday before three further league fixtures against Preston North End, Queens Park Rangers and Hull City ahead of the January 31 transfer deadline.
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