Texans general manager Rick Smith called the situation "very difficult" because Johnson has so much time left on his current deal.
"It is because it's something that's not customary, that's not common," Smith said.
Still, Smith said he's willing to talk with Johnson, who's represented by his uncle, Andre Melton.
"I'm not real worried about that because we redid him with two years left on his original deal, and that was three years ago, and over the first three years of that deal -- even if you ask him -- he's been well compensated," the GM said.
"One of the things that was real smart on his part was the fact that he was upset that we had not been able to come to terms with an agreement, but he came back and was a part of the offseason workout and he was with his teammates, he was a leader and he did things the right way," Smith said. "He played his contract out, and he was rewarded (with a six-year, $48 million contract extension this offseason)."
Johnson's absence is another distraction for a team that has been dealing with linebacker Brian Cushing's upcoming four-game suspension for testing positive for a performance-enhancing drug. The 2010 season could be a pivotal one for the Texans, who are coming off their first winning campaign but have never reached the playoffs.
"You'd like to have all your people out here working, especially when we're trying to go do something we never have done," Smith said. "So the ideal situation is to have everybody working together, but as we talked about last week, you've got to be able to deal with distractions."
Smith said he has spoken to Johnson, but he wouldn't divulge details about their conversations. The Texans have a mandatory minicamp scheduled for June 14-16, but it wasn't immediately clear if Johnson would attend.
The Associated Press contributed to this report.