MANKATO — If there is one thing Chad Greenway has learned during his seven years in the NFL it's that change is inevitable.
For Greenway himself, things have been fairly constant. Ever since he was inserted into the staring lineup in 2007, he has been a mainstay at the strong-side linebacker position.
And he has gradually improved. Last year, for the first time, he was selected to the Pro Bowl. Head coach Leslie Frazier believes the honor has given him more confidence and has enabled him to become a team leader.
But while Greenway has been a fixture, the same can not be said for the other members of the linebacking corps. This season, in fact, most of the remaining linebackers consist of either new faces or guys playing different positions.
"That's the nature of the league," said Greenway, who led the team with 148 tackles in 2012. "Things change; people come, people go. You just adjust and try to become the best unit you can."
The most significant change among the linebackers is the switch of Erin Henderson from the outside to the middle. Last year's Jasper Brinkley experiment didn't work out very well, so the coaching staff went to work converting Henderson almost as soon as the season was over.
"You always want to have your best 11 guys on the field," Frazier said. "We believe this will allow us to do that."
Greenway agrees: "Erin has had the whole offseason to work on it and he's coming along fine. It's a big adjustment but Erin has been around the league and he knows what's required. The more he works at it the better he'll become."
Another significant move by the Vikings was the decision to sign former Green Bay linebacker Desmond Bishop as a free agent. It's a gamble, considering Bishop missed all of last season with a torn hamstring, but it was one the coaching staff was willing to take.
Bishop has started training camp working mostly at the weak-side linebacker spot. Marvin Mitchell and rookie fourth-round draft choice Gerald Hodges from Penn State are also in the mix at that side.
Greenway contends a lot of people may be overlooking Mitchell who received some quality playing time last season.
"He played a lot and got some good experience with us," Greenway said. "I think he could have a very good year."
Mitchell, 6-foot-3, 249 pounds, was drafted by New Orleans in 2007. He played four years in New Orleans and started in the Super Bowl the year they won it all.
He played one year in Miami in 2011 and then signed with the Vikings before last season. He started two games at weak-side linebacker last year when Henderson got hurt.
"I was held back a little bit by injuries last year but I think I did OK," Mitchell said. "I'm healthy now and I'm competing for a starting spot. Everybody on the team should approach it like they're competing for a starting spot."
Second-year player Audie Cole is in the mix at outside linebacker, and Tyrone McKenzie is back for a second year with the team on the inside. Michael Mauti, another Penn State product, was drafted in the seventh round this spring and could also help at the middle linebacker spot, although he's probably more of a long-range solution.
"It's a pretty good group," Greenway said. "We just have to learn how to play alongside each other.
"It's a lot like an offensive or defensive line. You need to know what the other guy is doing and where he's going to be on a particular play. That's something we can work on in the preseason."