"In his magnificent nine-year career, Texans receiver Andre Johnson has missed more than three games one time.

In 2007, Gary Kubiak's second season as coach, Johnson suffered ligament damage in his knee and missed seven games. The Texans went 2-5 without him.

On Monday, Kubiak disclosed that the Texans don't know the extent of Johnson's hamstring injury, despite multiple MRIs. Now Johnson is headed for a second opinion and perhaps a third before they'll have a proper prognosis for his return.

"It's hard for me to give you an answer right now," Kubiak said at his regular Monday news conference. "He's going to miss some time. I don't know if that's three or four days. I don't know if that's a few weeks."