Russell Martin believes Swansea City's priorities in the summer transfer window became clearer after their emphatic 5-1 loss to Nottingham Forest.
Steve Cooper's men struck four times in the second half after Michael Obafemi had cancelled out Jack Colback's opener in the opening 45. Defeat brought an end to Swansea's impressive nine-game unbeaten run.
Forest ended the contest having had 17 shots on target, with a further 10 off target, despite seeing just 30% of possession. Martin admitted post-match that he had learnt a lot about some of his players after their capitulation in Nottinghamshire.
Read more: Sam Surridge hits hat-trick as Steve Cooper's Nottingham Forest claim emphatic win against Swans
"I thought the first half was great, we took the sting out of the atmosphere and controlled it for long parts," he said. "We had some really good moments. Their scary moments came from set-pieces and on the counter attack, which is something they're brilliant at.
"Then we just totally cost ourselves the game after 10 minutes in the second half. Then it's about trying to stay brave, and we didn't do it anywhere near well enough. The willingness to run in the last 20 minutes was nowhere near good enough.
"What we've learnt from the Bournemouth second half and this second half is that we certainly need a bit more presence and athleticism next season, there's no doubt. Today's been embarrassing, the second 45 minutes. The supporters didn't deserve that, and the players and staff didn't deserve that for the way they've worked.
"It's a real sign of what we are lacking and how to respond when we go behind. Today we learnt a bit about a few guys as well. I'm just really disappointed for everyone that we've finished the season away from home like that.
"The reality check is that if you're not going to really look after the ball and keep it as far away from our goal as possible, then you have to be wiling to fight and defend, and we haven't been able to do that. We know now what we're lacking for next season.
"Ultimately the players have worked hard all season. Everyone has. They've grown so much. It's been pushing a rock uphill all season to get to a certain point. They're in a position now where they can cause teams at the top of the table problems. We have to respond next Saturday because I don't want to finish the season like that. We were nine unbeaten before today, but it was really humbling in the second 45 minutes."
Swansea are bidding to bolster their defence in the summer window, with at least one tall and athletic centre-back featuring on their wish list. Their defensive frailties were fully exposed by promotion-chasing Forest, with Sam Surridge scoring a hat-trick against his former employers while Alex Mighten notched his side's fifth late on.
The SA1 outfit are also expected to be in the market for a goalkeeper, at least one wing-back and a midfielder. The Swans end their debut campaign under Martin against Queens Park Rangers next weekend. Kick-off in south Wales is at 12.30pm on Saturday, May 7.
