You don’t criticise individuals, but your either being dishonest or delusional if you’re saying the players couldn’t have given more.He doesn't need to be honest to the media either by the way. As much as I disagree with his assessment here, it's obvious that he doesn't want to criticise the players in public and there's nothing wrong with that.
Saying things like that is going to increase the frustration of the fans and turn people against him it’s actually going to be counterproductive and just creates different problems.