Vikings ready to go green in the middle The genesis of Mike Singletary's hall of fame career came in 1981, when he became the Chicago Bears' middle linebacker for nine games of his rookie season. Over 172 regular-season (and 12 playoff) games, Singletary became the command center of the Bears' iconic defense, his eyes seemingly burning out of his helmet as he directed the "Monsters of the Midway." But asked what he remembers about running the Bears' defense as a young player, Singletary simply replied, "Being very frustrated." "(It was) just trying to learn it all, just trying to not make mistakes, not trying to slow the defense down," he said. "The development of the middle linebacker is really predicated on how fast he can assimilate information and get the defense going. If he slows down, it slows everybody else down. You don't want to start looking at you and saying, 'Hey, can you do this or not?' " It is into that role that the Vikings could thrust a young player during the 2013 season. They re-signed Erin Henderson to play the weak-side linebacker spot, and coach Leslie Frazier said Sunday, April 7, that the Vikings will not look to move Chad Greenway from the strong side, where he has made two consecutive Pro Bowls, to the middle linebacker role. Unless the Vikings, who currently have $4.4 million left under the salary cap, sign a veteran linebacker, they will head into 2013 with either a rookie or a seldom-used linebacker (Audie Cole or Marvin Mitchell) manning the middle of their defense. That kind of a move would require some faith on the Vikings' part. "We know we have to get one. That's no secret," Singletary said after the Minneapolis Sports Collectible and Autograph Convention in Brooklyn Center on Sunday. "When we do, we just have to teach him as much as we can, as fast as we can. It's going to be a lot of work."