The 19-year-old has received a number of plaudits for his Liverpool form this season, which could result in a place in Roy Hodgson's Three Lions squad.
"It's all kind of coming together at the right time for him," Johnson told the club's official website. "If he keeps playing the way he is, he's definitely got a chance to be involved in the summer.
"I made my debut around a similar age as Raheem, but obviously I had a few years where I was in and out, so I didn't get as many caps as maybe I should have by now, but hopefully Raheem won't have that gap and I'm sure he'll go on and get more."
In the Premier League, Liverpool are currently at the top of the table with a two-point lead over Chelsea.