The England international will join QPR on a free transfer when his current contract with Fulham expires at the end of this month.
“I’ve worked closely with Mark before and there are also players here that I’ve played with previously, including Bobby Zamora and Shaun Derry,” the 31-year-old forward told his new club’s official website.
“Those were factors in me joining, but this is a big, big club and I’ve spoken to the chairman and Mark, both have great ambition for QPR, and it’s something that I wanted to be part of.”
Johnson added: “Mark was brilliant when I was at Fulham. I’d just come off the back of a rough spell with a knee injury and he guided and helped me through that period.
“He was great to play under. He’s a top manager and has some fantastic staff around him.
“Being an ex-player, he knows what the players want and expect. He’s excellent with the players. He speaks to them and he’s on the same level as them.
“He said it’d be great to team up again and that he was thrilled about the possibility of me joining QPR.
“He told me about the plans for a new training ground and how the club wants to go forward. That really excited me.”
