"We did well to get ourselves back into the game on Sunday but to concede three goals is disappointing," said Baines.
"Maybe you could say it's a lapse of concentration. The first goal was sloppy, there were three or four different occasions we could have cleared. And for the third again, they had two men in the box and we had five and they managed to get a clear header.
"We've got to highlight the goals we concede. The manager spoke to us about that.
"Ultimately we have to look to be positive and look forward. We have some time off and time to work on a few different things with the lads who aren't going away on international duty."
Despite the defeat at St James' Park, Baines believes morale remains good with Everton due to discover their group opponents in the UEFA Cup when the draw is made in Switzerland today at 11am.
"Everyone is down from having lost the game but it's been a decent week," said Baines to evertonTV. "We are in a reasonable position in the league and had a few wins.
"It's important we got through in Europe so there's no need to be too downhearted."