For more than 20 years, Falcons quarterback coach Greg Knapp has worked with the group of players coming into the NFL.

For years this work was done in obscurity, but with the proliferation of TV coverage of the scouting combine, Knapp is a regular during the quarterback sessions and on the NFL Network coverage.

He’s an authority on the position and has seen the advent of the mobile quarterback up close, from Michael Vick to Lamar Jackson.

When the Falcons (4-8) face the Los Angeles Chargers (3-9) on Sunday, rookie quarterback Justin Herbert, who’s surprisingly mobile at 6-foot-6 and 236 pounds, will be on display. The game is set for 4:25 p.m. at SoFi Stadium in Inglewood, Calif.

“Having done the combine for 20-plus years, being on the field, interviewing these players from all different types of backgrounds, studying the film every year, the evolution of the college game obviously is trickling up to the NFL game with the run-pass options, with the mobile quarterbacks,” Knapp said.

“The no-huddle stuff. It really has benefited a lot of coaches in the NFL that these young players in college are getting a lot of pass attempts, no matter what their style of offense is.”

Knapp was Vick’s offensive coordinator with the Falcons from 2004-06. He later served as Peyton Manning’s quarterback coach with the Denver Broncos when they won Super Bowl 50.

“In the college game, they spread out the field so much more that you do need the mobility of the quarterback in the college game,” Knapp said. “It doesn’t always mean that’s the proven answer, that he’s going to be a winner.”

In the Falcons’ 21-16 loss to the Saints on Sunday, they kept the mobile Taysom Hill under wraps until he slipped containment from defensive end Charles Harris and broke loose for a 43-yard gain.

“It was man-to-man,” Hill said. “It’s interesting, in the first half, we were getting a lot of two-man (double coverage) on third downs. So, as a quarterback and as a guy who can run, you’re kind of licking your chops when you see that.

“I was aware of it, I don’t recall if that was two-man, but it was man-to-man, no one was there for me, so I was able to escape the pocket and make a good play.”

It was the key run in a touchdown drive in what turned out to be a one-score loss for the Falcons.

Teams have been selecting more mobile quarterbacks in recent years.

Buffalo’s Josh Allen, Houston’s Deshaun Watson, Kansas City’s Patrick Mahomes, Chicago’s Mitchell Trubisky, Arizona’s Kyler Murray, the New York Giants’ Daniel Jones, Miami’s Tua Tagovailoa and Jackson all can run.

Other mobile quarterbacks are just moving around to extend pass plays, such as Seattle’s Russell Wilson, Green Bay’s Aaron Rodgers and Mahomes.

Herbert has rushed 41 times for 185 yards and three touchdowns.

“You know how talented of a thrower that he is,” Falcons interim coach Raheem Morris said. “You know what he can do with his arm. You can see the stats. You can see the talented group of wideouts that he has. But when things break down, he can use his legs.”

The Falcons consider Herbert a running threat.

“Shockingly enough, he runs better than you want him to,” Morris said. “He’s a really good runner. He’s athletic. He’s a big man. He has the ability to get out of the pocket and move it down the field.”

The Falcons may put a spy on Herbert.

“You better have somebody on him and be protected when he does break the pocket,” Morris said. “He could make a big play, a la Taysom Hill, like he did last week.”

Falcons quarterback Matt Ryan will move around to throw. He has run 23 times this season for 73 yards and touchdown. A league MVP, Ryan has had his winning seasons when the interior of his passing pocket has been firm.

“He’s played extremely well for not only a rookie, but for anybody,” Ryan said. “He’s gone out there and has been really competitive and very accurate. I think he’s only going to get better. He’s going to do a great job moving forward.”

Falcons defensive coordinator Jeff Ulbrich recognizes mobile quarterbacks as potential threats.

“The mobile quarterback, in my opinion, has the ability to really own the time of possession because he’s a guy who can constantly move the sticks,” Ulbrich said. “You can’t pressure them necessarily like you want to because your rush lanes have to be perfect. You can’t give this guy an escape.”

Teams try to rush wider and keep the mobile quarterbacks in the pocket.

“Then you have to be careful about certain coverages,” Ulbrich said. “When you’ve got coverages with eyes on your man and not on the quarterback, if he were to break free of a three- or four-man rush, he’s out the gate. So, appointing a guy to him when you are playing some of those man-to-man, two-man principles.”

Ulbrich acknowledges the fine differences in mobile quarterbacks.

“There are two separate types of mobile quarterbacks,” Ulbrich said. “There’s the ones that scramble to run and those that scramble to throw. They are both pains in the butt. They both have their own unique challenges. (Facing the Chargers) is going to be no different. We’re going to have to appoint a guy to (Herbert) at times.”

Chargers coach Anthony Lynn planned to bring Herbert along slowly and play with veteran Tyrod Taylor this season. But Taylor suffered a punctured lung Sept. 20 when a member of the team’s medical staff was giving him an injection.

Herbert was forced to start against Kansas City and has been playing since.

“Under the circumstances I think he’s done well,” Lynn said. “He’s always handled himself in a very mature manner. I think playing four years of college kind of helped the process.”

The Chargers drafted Herbert sixth overall out of Oregon after parting ways with long-time signal caller Philip Rivers.

“Yes, he brings some mobility to the position where you can do some different things,” Lynn said. “You can move the pocket. Sometimes you can make the defense play 11-on-11. That’s always fun.”

Lynn believes the league will have more mobile quarterbacks in the future.

“When you look at high school football and you study the game, you know what’s coming,” Lynn said. “Now, it’s what you see in college. Now, that’s what you see a lot in this league.

“These young men are in these seven-on-seven camps so often now that they are athletes, but they also can throw from the pocket. They can throw on the move and they can run. That just puts a tremendous amount of pressure on the defense.”

Quickly reading defenses will remain a key skill set for the quarterback position.

“I still believe this strongly, you’ve got to have a decision-maker at quarterback that can throw from the pocket on third downs and in the red zone, where things are happening a lot differently than they do in college,” Knapp said.

The speed of red-zone plays in the NFL presents tighter spots to pass into. Players are not open very long.

“Because of the defensive blitz schemes on third downs, you don’t have as much time to see things and the complexities of the coverages,” Knapp said.

Overall, there’s a major benefit to having a mobile quarterback.

“Without a doubt, the mobile quarterback gives you an advantage because at times he can take and broken down play and extend it,” Knapp said.

Falcons’ final four games

Falcons at Chargers at 4:25 p.m., Sunday

Buccaneers at Falcons at 1 p.m., Sunday, Dec. 20

Falcons at Chiefs at 1 p.m., Sunday, Dec. 27

Falcons at Buccaneers at 1 p.m., Sunday, Jan. 3

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