The ??16m summer signing did not make the matchday 18 for the goalless FA Cup fourth-round draw at home to Bolton despite being fit after illness.
Rodgers said he spent an hour on Friday telling the Italy international exactly what he had to do in order to be considered.
“I am judging it every day in training – Mario is exactly the same as every other player, there is no special treatment for anyone,” said the Reds boss.
“Fabio Borini and Rickie Lambert are working tirelessly in training and when they go on they have contributed and young Jordan Rossiter, on the bench today, has been brilliant in training and I have to judge it on that.
“If you want to contribute you have to be at it every single day in training in order to be in the squad on matchday.
“We had an hour or so yesterday chatting and he understands where he is at. He knows exactly what is required to be in this squad before he can be in the team.
“It is difficult for him but he knows the level of what this team is at – you see the aggression in our pressing and if you can’t do that you are not going to be a part of what this team is trying to achieve.”
Another striker, Daniel Sturridge, returns to training on Sunday having not featured for the Reds since August 31 because of a thigh injury and could make the squad for the second leg against Chelsea on Tuesday.
Liverpool lacked a cutting edge against their Championship visitors, although goalkeeper Adam Bogdan did his part to earn a replay with some good??saves.
However, Rodgers felt Matt Mills should have been dismissed for pulling down??Lazar Markovic early in the second half.
“We did everything but put the ball in the net,” said Rodgers.??”Creative-wise we were excellent and were defensively solid against a form team in the Championship.”
Bolton boss Neil Lennon was delighted with the chance to take Liverpool back to the Macron Stadium.
“On the outside people would say Liverpool didn’t play well but they played very well,” he said.
“We were resolute, disciplined and we created a couple of our own chances as well.
“To come away from here with a draw having watched Liverpool on Tuesday night playing exceptional football is more than I could have asked for.”