The move to leave Johnson, 32, out came after the former Fulham forward suffered a serious knee injury in September, with suggestions he could remain sidelined for the remainder of the season.
Johnson has now revealed he is almost ready to return to full training but will remain a spectator as Harry Redknapp looks to guide the R's top-flight safety.
"The knee is great, I've been working hard in the gym and finally got outside a couple of weeks ago," he told QPR Player.
"I'm not too far away now. I went to see the surgeon and got the go ahead now to crack on to the next stage. Hopefully within the month I will be back training with the boys."
The decision to omit former England international Johnson from the squad could come back to hurt QPR, who have let Djibril Cisse and DJ Campbell leave the club while Bobby Zamora is playing through a hip injury and January acquisition Loic Remy has also been in and out of the treatment room.
"Because of the 25-man system this year I haven't been named in it so it is impossible for me to play this season," Johnson said.
"It would just be great to get a couple of games under my belt with the reserves and have six weeks or two months training with the first team."