His value to the coaches and players, though, has never been greater.
"We all love him," free safety Harrison Smith said. "A lot of guys try to follow his lead."
Like Sunday, for example, when Greenway grabbed a deflected pass and took the interception 91 yards for a touchdown to seal Minnesota's 31-14 victory over San Diego. He had more than half of the defense accompanying him on the return and the entire sideline exuberantly encouraging him into the end zone.
"That was quite the convoy," Greenway said.
At age 32, this might be Greenway's 10th and final season in the NFL. Drafted in the first round out of Iowa in 2006, he has become the rare player to stick with the same team the whole time.
Still the starter at the weak side linebacker spot in the base defense, Greenway comes off the field for the nickel package. With so many pass-first teams now, that means he's on the sideline far more than not.
Against the Chargers, Greenway was on the field for 19 of 72 plays, relegated to mostly running downs. He realized this was coming, after taking a pay cut for the second straight year. So he has become even more of a leader at a position with two rookies and three others who entered the league in 2012, 2013 and 2014.
The investment of draft picks in 2015 (Eric Kendricks, second round), 2014 (Anthony Barr, first round) and 2013 (Gerald Hodges, fourth round) by the Vikings is all-telling in terms of their future plans at linebacker, making Greenway's presence all the more important.
Coach Mike Zimmer said he told an unnamed younger player, presumably one of those aforementioned draft picks, after the game Sunday to keep trying to emulate the way Greenway approaches his profession, prepares for each opponent and handles himself off the field.
"I said, 'This guy can be a great mentor to you,'" Zimmer said, later adding: "He's always trying to learn. He's eager to be a great football player all of the time. Those are the kind of things that I really respect about him."
While he's playing his smallest part yet, this group has the potential to be one of the best defenses Greenway has been on. His decreased playing time is not solely a function of his age and future, but a reflection of the greater depth the Vikings have up and down the defense now.
"I know my role now is to play against certain personnel groups and come in and out in the base defense, and I've tried to just make that my own and be the player I've always been in that position," Greenway said.
The Vikings (2-1) are fifth in the NFL with an average of 16.7 points allowed per game and tied for fourth with an average of 6.4 yards yielded per pass attempt, two vital statistics for any defense.
The key to their success, naturally, has been persistent quarterback pressure from the creative blitz calls by Zimmer and the natural pass-rushing ability of the defensive line.
Their past two opponents have sure felt it. Detroit's Matthew Stafford and San Diego's Philip Rivers each took plenty of painful hits, and neither of these prolific quarterbacks had a particularly difficult day. Vikings cornerback Captain Munnerlyn said he heard Rivers pleading to his injury-depleted offensive line at one point Sunday for better protection.
"'Man, don't let me get hit like that again,'" Munnerlyn said, quoting Rivers.
That's what Zimmer has been pushing for.
"Football has been around so long, and it always comes down to a physical game at the end," Zimmer said. "I want us to continue that way. I hope that that is our identity going forward, but we'll see. We've still got a long way to go."