Johnson was a late withdrawal for the Dogs' 72-point win over Richmond at the MCG on Sunday.
But coach Rodney Eade said Johnson had been kept out by a virus, not an injury aggravated by a drinks cart hitting his leg during a midweek training session.
Eade said Johnson hurt his achilles in the accident, not the calf which had been troubling him pre-season.
"Brian Lake had [the virus] and Shaun Higgins had it early in the week and Brad got it later in the week, although not as severe," Eade said.
"But we just err on the side of caution, because his energy levels were down and he's only played the one game - 70 per cent or whatever it was - so was it a recipe for a soft-tissue injury?
"I think he'll be right for next week."
Johnson became the 11th player in league history to reach 350 games in round one.
