Jenas slammed after penalty miss
The game finished 0-0 after 90 minutes, and moved into sudden death of the penalty shoot-out when Jenas stepped up and attempted an audacious clipped effort.
Much to his horror he got his effort all wrong and it flew over the bar.
Magpies chief Robson has claimed he would never criticise players who wanted to take penalties and then missed them, but felt Jenas` attitude was all wrong as he went to take his effort.
"All players have the right to take penalties the way they think," said Robson. "I will not criticise if they miss them.
"I have lost a World Cup semi-final in similar circumstances. I will never complain about players missing penalties and have the utmost sympathy for them.
"But in JJ`s case I think it was outrageous. It is obscene what he`s done and you can`t do that.
"We have spent hour after hour together on shooting.
"But he has made a mistake and I have told him that. I have told him he has been unprofessional.
"He will learn from that, but he has been part of a Newcastle team that has worked really hard.
"He is a good young pro, and he will learn from that.
"In the year we`ve had him he`s made good strides but he has made an outrageous error and he will have to learn."