The head coach was pressed on Hernandez' absence throughout his post-game press conference, but would give no further explanation.
He revealed midfielder Jamie Shackleton picked up a knock in training yesterday and Hernandez, who reacted angrily to being substituted in Monday's loss to Leicester City, was not one of the players he considered 'apt' for the game. There was a place on the bench for teenager Jack Jenkins, who played for the Under 23s on Friday at Newcastle United.
"Shackleton had a knock in training yesterday. Pablo is fit, he wasn't in the squad for today's game," he said.
"I evaluate all the players for the upcoming game and didn't pick him for this game. If you feel the decision was strange, I choose the 18 players I feel are apt for the game.
"I didn't pick [Jack] Jenkins in the place of Pablo. The response to your question I have already given. I reiterate, I picked the 18 players I feel are in the best conditions for the upcoming game. You can qualify my decision as a wrong one given the arguments you gave.I have already explained the decision, there is no point in insisting. He was available and I picked other players."
Hernandez had huge influence in Leeds' title run-in, despite managing an injury and made match-winning contributions in a number of games for Bielsa.
This season he has missed games through a groin strain and then had to await a chance to start thanks to the form of record signing Rodrigo in the number 10 position. Rodrigo's close contact with someone who tested positive for COVID-19 gave Hernandez his opportunity against Leicester but he was withdrawn after 67 minutes and showed his frustration on a long walk around the pitch, before kicking a bottle as he reached the dugout.
Bielsa was quizzed about the midfielder's reaction on Monday night and said: "If he chooses to kick a bottle because of my decision, what can I do?"