Patterson is expected to be in contention to make his Altrincham debut on Saturday afternoon.
The 21-year-old is highly rated by the Black Cats, but Johnson is determined to ensure he gets 25 starts during the campaign to develop his game.
It has become a more difficult task on Wearside due to the arrival of Thorben Hoffmann from Bayern Munich.
Notts County goaltender Sam Slocombe is believed to have suffered an injury in training this week, opening up the opportunity for Patterson.
County boss Ian Burchnall has worked with Sunderland goalkeeper coach David Preece in Ostersunds, Sweden, which will help the Black Cats monitor his development closely.
The Magpies have made an excellent start to the National League season, with fifteen points in seven games.
They are currently in fourth place in the ranking.
“He joined a movement to play on Saturday.
“That’s the level we wanted to put him at, and a great club with a great stadium and a great fan base.
“He will do very well for them.
“I think the structure is that it’s going to be monthly for now, which means you can pull them out on some sort of 24 hour notice if there’s an emergency for that.
“It’s a great decision for him. They have a brilliant young manager and their style is quite similar to ours in the way they use the ball.
“It’s a gift to me because I think it will improve their team.”