Johnson missed nine games last season with hamstring injuries and was sidelined from the first organized team activities in the spring after arthroscopic surgery on his left knee. The five-time Pro Bowl selection started Sunday morning's practice and pulled up during a one-on-one drill.
"We don't think it's anything significant," Kubiak said. "Obviously, Andre's worked so dang hard to get back and get back on the field full speed, so it's disappointing. But I don't think we're staring at anything significant."
Kubiak said Johnson wanted to continue practicing, but Kubiak took the cautious route. Johnson watched the rest of the outdoor half of the workout with a towel wrapped around his head, then went to Reliant Stadium when the practice moved indoors. Kubiak expects Johnson to miss "a few" practices, though he couldn't set a timeline.
"We'll be smart with him," Kubiak said. "We want him out here as quickly as possible. I'm not too concerned, from what I'm hearing."
Johnson sat out 3-4 weeks after his knee surgery in May, and he turned 31 in July. After playing in all 16 games in 2008 and '09, Johnson sat out three games late in 2010 with a sprained right ankle. Last year, he hurt his right hamstring against Pittsburgh in October, then hurt his left hamstring against Atlanta in December.
When he arrived at training camp on Friday, Johnson dismissed the notion that he was getting too old to be an effective receiver.
"No, I don't feel old at all," he said. "It's a new season, new training camp. I'm healthy and I'm ready to go at it again."