Jones admits defeat to Southampton wasn't good enough.
He told Liverpoolfc.com: "I got stopped by someone the other day in the supermarket and he was saying how frustrated he was. I said to him, 'It's the same for us.'
"We know what effort we put in every day in training and going into matches. The preparation, you know it's right but sometimes on the day it just doesn't happen for us. That's where it's the most frustrating.
"Sometimes it can happen where maybe one or two players aren't really at it, but in 11 you can cover it up and people maybe don't notice. If there's a day where maybe five or six aren't 100 per cent, you're going to struggle."