"Maybe the effort was questioned a little bit and the lads need to raise their game.
"You've got to put on a performance but not enough players did last night."
Jones felt there was an absence of motivation last night.
"Although it's only a friendly, you've got to get your mentality right for these games," he said. "They are difficult to play in. It's easy to get yourself up for Premier League games - you're just ready.
"But games like last night is more of a test of your mental strength - can you get up for games like that?
"It was disappointing. You don't want to lose any game, whether it's pre-season or a competitive game."