All Griffin needed was his wife and a couple of members of the Ravens staff.
Lining up in the shotgun, Griffin had his wife, Grete, "hike" the ball by tossing it to him underhand. He then fired passes about 30 yards downfield as his 1-year-old daughter, Gloria, stood nearby.
From this impromptu throwing session to Thursday night's preseason game against the Los Angeles Rams, Griffin has repeated these words: Seize every opportunity.
"The perception is that a lot of times when you look at the history of the league, guys who get drafted high and they don’t make it with their first team and get another chance and something happens -- they traditionally don’t get another chance," Griffin said. "I think part of the reason is those guys end up quitting and end up giving up. They lose their love for the game. They lose their passion."
Griffin then added, "I’m not going to quit. I’m not going to give up. I haven’t lost my passion for the game."
Griffin, 28, easily could have tapped out on his NFL career. In a matter of five years, he went from being the No. 2 overall pick with the Washington Redskins and the NFL Offensive Rookie of the Year to being out of the league for an entire season.
The odds of him playing again after being released by the Browns in March 2017 were "very, very low," he estimated. Griffin knew his injury history -- concussion, torn ACL, dislocated ankle and broken bone in his left shoulder -- scared away teams.
But Griffin continued to stay in shape, throwing to receivers at Central Florida. He repeatedly watched NFL games, putting himself in the quarterback's situation and seeing how he would execute the play.
This preparation led to an impressive workout for the Ravens, and a one-year, $1.1 million contract. It's a mindset that catapulted him to a start in last week's Hall of Fame game, where Griffin completed 7-of-11 passes for 58 yards and one touchdown. If Breshad Perriman had held onto a pass -- instead of letting it go through his hands for an interception -- Griffin's passer rating would have been 117.2.
Griffin acknowledged he shed some tears in his first NFL game in 19 months.
"I can say I had no doubt, and I worked as if I had no doubt. But I wasn't in the league last year." Robert Griffin III
"I felt like I had earned that start by my performance and by what I’ve done with my teammates," Griffin said. "That meant a lot to me. It meant even more having gone through what I went through, being out of the league and not knowing. I can say I had no doubt, and I worked as if I had no doubt. But I wasn’t in the league last year."
In the last full practice before the Rams game, Griffin was on the field for only six to seven reps, which spurred him to throw extra passes afterward.
"What stands out for me for Rob Griffin is that he’s a pro. He’s a constant pro," coach John Harbaugh said. "He’s very upbeat all the time. He knows what he’s doing, and he knows how to operate. Beyond that, he’s playing very well."
Griffin's fate with the Ravens might be out of his hands. If Jackson proves he can be the primary backup to Flacco, the Ravens may decide against keeping Griffin. If Baltimore is unsure whether Jackson is consistent enough to be the No. 2 quarterback, the team could hold onto Griffin.
Despite this situation, Griffin has helped Jackson, whose success could lead to Griffin's exit in Baltimore.
"You’re not going to cheat a guy to beat a guy. Right?" Griffin said. "I’m not going to try to cheat you and not tell you something and not help you to try to win a spot. We’re all about the team here. We’re all about the Ravens. There’s no bad blood in our room. Our room is a very cohesive unit, and we’re all going to go out and ball out."
History isn't on Griffin's side. The Ravens haven't carried three quarterbacks since 2009, when Flacco, Troy Smith and John Beck were all on the roster.
"I don’t let my mind wander to, ‘Well, what’s going to happen?" Griffin said. "I don’t worry about that. I let all the chips fall where they may. I’m going to continue to work hard and prove it to the coaches, so that I can be here and show them that I’m an asset to this team. I think I’ve done that to this point and I’ll continue to do that as long as they let me."