"I'm devastated," Johnson said. "This was the highlight of my career.
"You can't imagine how much the medal means to me. It is something you want to treasure for your whole life and show your kids and grandkids.
"I'm just hoping that if I can't get it back the FA might consider making a replica for me, because it's so soon after the match itself maybe they can see it as exceptional circumstances."
Pompey chairman Peter Storie believes the thefts were premeditated, and said: "If someone has taken these medals, they have deprived our players of their lifelong dream.
"The medals appear to have been taken from the hotel, which is unfortunate because they looked after us so well for three days we were there.
"Clearly, someone has come in from outside knowing that these medals were about and focused on taking them."