Zamora had just broken into the England set-up when he was injured in mid-September against Wolves, leaving the 29-year-old facing several months on the sidelines.
Johnson told the club’s official website:“I was absolutely devastated for Bobby. He had a fantastic season last year and was Player of the Season for me. He’s a top, top man.
“He didn’t have the best of luck during his first season, but he stayed strong. It wasn’t his performances, it just wasn’t happening in front of goal but that all changed last year.
“The fact that he broke into the England team – he could have had that spot. I still think he will have that spot, but the timing of his injury was gutting.
“Emile Heskey had just retired from international football and Bobby had just played his first game. He was cemented in that squad and should have been starting.
“I can’t really express how gutted we all were for him.”