Banahan was the third England played to be cited on the tour following lock Dave Attwood and fellow wing Mark Cueto.
While both of them escaped punishment, the Bath star's suspension will see him miss both the second Test against Australia as well as the final tour game against the New Zealand Maori.
And while England bagged their first win in the Southern Hemisphere since 2003, their display was far from convincing with the attacking game yet again failing to fire.
Yet Johnson maintains his squad are not being shackled by too many instructions from his coaching staff.
He said: "Am I saying, 'it was fantastic'? No. There are some things we need to do better. But -ultimately I thought it was a good performance in tricky conditions.
"I'm happy the players aren't being overloaded, absolutely.
"Some of it is individual stuff for one player, 'watch this, watch that' kind of thing. Some of it is tactical, some of it they already know.
"You can do that, although part of being a player is knowing what you're doing and concentrating."