Keller suffered the injury when he was tackled in the second quarter of Saturday's game and ESPN reported that he had suffered three torn ligaments and a dislocated knee cap.
The 28-year-old joined the Dolphins in the off-season after spending four years with AFC East rivals the New York Jets.
The Dolphins were not immediately available to comment.
After the game, which Houston won 24-17, Miami head coach Joe Philbin said: "You all saw Dustin Keller get carted off the field. I hate to see any player in that situation. We are all wishing Dustin well and we hope his return is sooner as opposed to later."