Johnson has a host of key senior players currently sidelined, with his first-team group desperately short of options in the full back and central midfield positions in particular.
Johnson will again turn to a core of the U23 group in the Papa John's Trophy first knockout round, and says that there is a 'serious opportunity' for those involved.
Not least because a change of rules in the Carabao Cup means there are to extra squad spaces up for grabs for the quarter final at the Emirates Stadium.
"I think they have to be [in consideration for league minutes]," Johnson said.
"This is what we've got to prepare them for.
"You look at these players and you expect to get five or six first-team games out of them, and that's really good for them because they're also getting their U23 games and some of them will go out on loan.
"At the moment, we're so short at first-team level that we've got to trust them, throw them in.
"We want to win against Oldham, but at the same time we have to protect a lot of our players going into Saturday and the run of fixtures that we've got in the league.
"But these young players... they have got a serious opportunity right now.
"We've got Arsenal coming up in the Carabao Cup later this month and you can have 20 in your matchday squad. At the moment we've got about 13 or 14 fit senior players.
"So if I was one of these young players, I would be doing some serious running against Oldham."
Johnson is set to use a number of young players against Oldham Athletic at the Stadium of Light on Wednesday night, and says it 'is a big challenge'.
Sunderland beat the same opposition in the same round of the Papa John's Trophy in Johnson's second game in charge a year ago, but with a far more senior side.
The head coach says this game will test how far the club has travelled, given that he will name a predominantly youthful XI.
"I want to see how far the club has come," Johnson said.
"I saw Oldham play against Ipswich recently, I know they haven't been in great form but they did well for 60 minutes.
"They had two or three players I really, really liked and then a lot of established senior players.
"You never quite know how the opposition are going to approach it, we know we're going to approach it with opportunities for younger players but also being strong and having some senior players in there.
"It's a big challenge and one I'm looking forward to.
"I want to see if we can play with that philosophy like we have done in previous games, and whether these guys can step up.
"They're building trust with me all the time, you saw we brought Will Harris on at Cambridge.
"Cieran Dunne and Stephen Wearne have been in the squad, Ellis Taylor as well.
"There's a lot that could be on show and hopefully the fan will enjoy it."