In the Vikings' 60-year history, four players have worn the No. 9 in a regular-season game: kicker Scott Sisson and quarterbacks Tommy Kramer, Jim McMahon and Brooks Bollinger.
On Tuesday, defensive tackle Sheldon Richardson tried it on, thanks to both the NFL's relaxed jersey number policies and the fact he was on the free agent market until long after the new rule passed in late April.
"I really don't mind numbers, but I wasn't wearing 67," he said Tuesday. "That's what they first gave me when I came out. I think I've got No. 9 just for minicamp, and hopefully we'll see what happens.