Wijnaldum admits Liverpool 'gave a half away' against Swansea
Jurgen Klopp's side saw their 18-game unbeaten run in all competitions come to an end in Wales thanks to a first-half goal from Alfie Mawson.
The Liverpool boss said afterwards that his side surrendered the match with their first-half display and Wijnaldum agreed that their improvement after the interval was not enough to erase the damage.
"That's how we wanted to play in the first half also, only we didn't," he told the club's official website.
"We're more disappointed because we gave one half away, we gave them their only chance and they scored a goal.
"If you play the whole game like we played the second half you would be disappointed but at least you tried. We didn't in the first half, we didn't do what we had to do."
3 - Jurgen Klopp has lost more Premier League games against @SwansOfficial than he has vs any other side in the competition. Clipped.
— OptaJoe (@OptaJoe) January 22, 2018
Roberto Firmino hit the woodwork with a header from point-blank range in the dying seconds and Wijnaldum admits he thought the Brazilian had grabbed an equaliser.
"I thought the ball was in but unfortunately it wasn't," he said. "We were not lucky in the finishing. You have those games. We must keep the confidence and look forward."
It was Liverpool's first loss since a 4-1 thrashing by Tottenham on October 22 but the Reds remain in fourth place in the table, two points above Spurs.
Wijnaldum now wants them to try to replicate the performances they showed during that run as soon as possible.
"We had the unbeaten run, it was a good thing," he said. "But it was only because we did the things we had to do on the pitch. We were 100 per cent concentrated and we were sharp from the first minute.
"That's what we have to do again."