Celtic threw away a two-goal lead in Dingwall to suffer their second consecutive Clydesdale Bank Premier League defeat after Steffen Wohlfarth headed an injury-time winner.
Lennon admitted after Celtic's Champions League campaign ended in Turin on Wednesday that some players would leave in the summer.
But he felt some had downed tools early after County edged the second half at Dingwall after levelling before the break.
Lennon, who made five changes following the 2-0 defeat by Juventus, most of them enforced, said: "These players owe me. I have pulled them out of places that no-one had heard of and put them in the shop window.
"And I want payback now. That is simply not good enough. If they want to go they only have to knock on my door and say 'I want to go' then I will leave them out and play someone else who wants to be here."
Lennon was without Victor Wanyama, Adam Matthews, Emilio Izaguirre and Georgios Samaras because of injury while he excluded Gary Hooper from blame.
Celtic are 15 points ahead in the SPL but Lennon had urged his team to wrap up the title as soon as possible.
"It has become a problem because we have lost the last two away games to really poor performances in some aspects of the game," he said. "I'm not happy with the attitude of some of the players. Some of them look like their minds are elsewhere at other clubs.
"I don't know if they have been tapped up, I don't know where they are mentally, but you can tell by their body language they are not with us at the minute and I'll have to sort that out."