CINCINNATI -- It all started with a Bulldog, and continued with a Yellow Jacket.
During the summer of 2011, while NFL players unable to workout at team facilities and unsure what their immediate futures held had to sit at home and play the lockout waiting game, two of the league's best young receivers teamed up in a familiar state down south to keep in shape.
That summer, A.J. Green, the Cincinnati Bengals' first-year wideout who once starred at the University of Georgia, was in Atlanta. So was his former Georgia teammate, Mohamed Massaquoi.
"Mohamed Massaquoi was working [at Georgia Tech]," Green said. "So I went out for a couple days and met him."
Green, just a wide-eyed rookie awaiting his first snaps as an NFL receiver back then, also ended up meeting Calvin Johnson, the Detroit Lions' large and beloved pass-catcher nicknamed the apropos "Megatron." A former Georgia Tech standout, Johnson was back in the city, too, training at the institute where his birth name and nickname first became synonymous with the freakish, circus catch.
Deep in Dixie, where college football passions run as thick and deep as Georgia red clay after mid-afternoon summertime rainshowers, a pair of supposed rivals came together for a cause league coaches like the Bengals' Marvin Lewis now praises.
"Calvin has been a great mentor to A.J., and they've been very close," Lewis said earlier this week. "It's been great the way Calvin carries himself as a pro and as a man. It's very similar to A.J."
This Sunday, for just the second time since their now clockwork offseason tag-team regimens began, Johnson and Green will be facing off at Detroit's Ford Field. Unlike that time, though, the pair will actually be playing for more than just a few preseason reps. Both players will be trying to help their respective team one-up the other's in a midseason game that could have all kinds of postseason implications.
Detroit enters the contest 4-2.
Cincinnati enters the contest 4-2.
Something will have to give.
Lately, it has been Johnson's knee and hands that have given in a bit. Three weeks ago, he missed the Lions' game at Green Bay because of a knee injury. Last week, he came back and played through it, but wasn't very effective, catching just three passes for 25 yards. He also had two drops.
Overall, Johnson has 24 receptions for 337 yards and four touchdowns this season.
Green, who has been targeted 22 more times than Johnson, has 37 catches for 464 yards and four scores. He comes into the the game one catch shy of 200 for his career. Now in his third season, he's about to play in his 38th game. It took Johnson 47 games to reach his 200-catch milestone.
"He had an outstanding first couple of years," Johnson said. "I'm about to tell him, you've got to come over, come take the reins over."
From the time his career began in 2007, Johnson has been widely regarded as the best player at his position. His combination of imposing size, raw strength and lightning-quick speed make him seemingly unstoppable. Most passes thrown within a 10-yard radius of him get caught. And when they do, he very seldom goes down right away. Typically it takes multiple defenders to slow down his yard-after-catch pickups.
Asked if he believed Johnson was the No. 1 receiver in the NFL, Green didn't hesitate with his response.
"I think so," he said. "He can do everything. He can go get the ball, run any routes, take a screen 80 yards for a touchdown."
Come to think of it. That kind of sounds like Green describing Green. He, too, catches most balls thrown his way, even if they require one-hand snags or acrobatic grabs. One of his best plays last week came on a screen that he turned into a big gain. After catching a quick pass at the line, he sprinted 54 yards by following his blockers.
So, could Green and Johnson safely be considered the same guy?
"Both of them don't have to be open for a quarterback to throw the ball to them," Lions coach Jim Schwartz said. "They are tall with great hands and leaping ability. ... Both have the quarterback's confidence that if they are covered, they can get it to them."
About the only thing that separates them is their size. Johnson is about an inch taller and 30 pounds heavier. He also is older, having left Georgia Tech one year before Green left South Carolina to begin his college career at Georgia. When he arrived, his quarterback was a senior from Texas: Matthew Stafford. That, of course, is the same Matthew Stafford who completes passes to Johnson in Detroit now.
When it comes to Johnson and Green's offseason workouts, as much mental work goes into them as physical.
"We get a good workout there, whether it be on the field, in the weight room, wherever we're at," Johnson said. "Even if we're just sitting there talking, it's just to understand his mindset.
"We're so cool right now, it's just like a [having] brother, you know?"
In the Peach State, it's an unlikely brotherhood: a Bulldog, one a Yellow Jacket.
ESPN NFL Nation reporter Michael Rothstein contributed to this report.