The 52-year-old Greene, who left Green Bay in the offseason to spend more time with his family, has been with the Eagles for only two of three days, but there was evidence of his teaching during Monday's practice at the NovaCare Complex.
"It was a very basic, fundamental way of rushing the passer that he's bringing to our guys," Davis said.
Linebacker Connor Barwin "sacked" off-limits quarterback Nick Foles during one set of team drills, after he and defensive end Fletcher Cox shared a "sack." And Trent Cole and Brandon Graham used aggressive moves against tackles in one-on-one drills.
But it was Travis Long, on the roster bubble at outside linebacker, who seemed to apply the lessons he learned from Greene when he drove rookie tackle Kevin Graf onto his back with a violent bull rush. A play later, he got around a defeated Graf.
"I'm trying to listen to him," Long said of Greene. "He came in and gave a presentation to us yesterday and broke down some of his game film. It's been very helpful."
Long, an undrafted rookie out of Washington State, spent all of his rookie season on the practice squad. But Chip Kelly and the Eagles have been touting his chances of making the 53-man roster.
His development has been a pleasant surprise and could spell trouble for veteran Brandon Graham. But the primary focus at the outside linebacker spot has been top draft pick Marcus Smith.
If the Eagles are to improve upon last season's second-to-last ranking in sacks per pass play and eventually make the complete transition to traditional 3-4 linebackers, Smith must develop in Year 1. Greene had essentially the same evaluation of Smith that Davis has had to this point: He has upside but is a work in progress.
"Athletic as all get out - no doubt," Greene said. "He brings a . . . big skill set to the table. So I'm whispering little sweet nothings into his ear every chance I can."
Smith, who played quarterback in high school, is raw when it comes to outside linebacker fundamentals. There is also the mental transition an offensive player switching to defense must make to be successful, and a lot of that has to do with aggression.
"Yeah," Smith said when asked if he had the kind of violent nature Greene was describing, "I'm a violent dude."
But some linebackers just don't have the ferocity necessary to run over a tackle who is more than 50 pounds heavier. Greene played at 6-foot-3, 247 pounds. But there weren't many edge rushers as feared.
Greene's 160 career sacks - for the Rams, Steelers, 49ers, and Panthers - rank behind only Reggie White and Bruce Smith. Davis, who coached Greene in Pittsburgh and Carolina, questioned why he was not in the Hall of Fame.
Asked why some players had the necessary kick-butt mentality and others didn't, Greene said, "I don't think that's a question that will ever be answered."
Davis will gladly take sacks. The Eagles had 37 last year - 20th in the league. But there's more to a thriving pass rush. Davis wants hurries, quarterback hits, batted passes, and general disruption.
"I want the defensive unit to disrupt the timing and rhythm of that quarterback and hit him as often as we can," Davis said. "Who it comes from, I think we've got a lot of guys."
The edge rushers should lead the way. Trent Cole, who notched all eight of his sacks in the second half last season, is the leading candidate, even at age 31. Barwin could get more pass-rush chances rather than dropping back as often as he did last season.
If Smith contributed much this season, it would be a surprise. Few rookie edge rushers have made immediate impacts.
But one who did was the Packers' Clay Matthews, who recorded 10 sacks as a rookie in 2009 with Greene as his position coach.
"All I had to do was polish an edge off that diamond, and I knew he was going to start shining," Greene said of Matthews. "There's a lot things in this young kid, Marcus. Athletic as he is, as fluid as he is, and as physical as he can be when he wants to be, he can be a fine player."