Turns out that, as with most matters concerning the Vikings and the NFL league office, the "line" was a steaming pile of crap.
According to Judd Zulgad of the Minneapolis Star-Tribune, Henderson was supposed to replace Saints' linebacker Jonathan Vilma, who had originally said that he couldn't take part in the game for "personal reasons," but then came back and said that he could play after all. So, Henderson trundled all the way out to Hawai'i, only to find out that he wasn't needed to actually. . .you know. . .play in the game.
Nicely done, Jonathan Vilma and the National Football League. Maybe the league can give him a formal apology while they're handing the Comeback Player of the Year Award that Henderson deserves to someone that deserves it significantly less. . .incidentally, that award will be given out this evening on the NFL Network at about 6:00 PM Central time.
On the bright side for Henderson, since he did have to schlep all the way out there for the game, he will receive the $45,000 winner's share for the NFC. Since it appears that he took at least a few of his fellow linebackers on the trip with him, he ought to just about break even.