Kubiak said Johnson seems to be well but is undergoing league-mandated concussion evaluation.
"He's doing great today," he said. "He's out. Rode the bike today. Doing great, but he is in the (concussion) protocol right now."
Johnson suffered the concussion during Sunday's overtime victory against the Tennessee Titans after hauling down eight passes for 76 yards.
"Obviously it will be an end of the week decision because he's gotta go through the process," the coach added. "But I think after the game, talking to him, seeing where he's at today, obviously he's doing really well. I would expect the progress to go pretty quickly if it goes like it has the last 24 hours."