ALAMEDA, Calif. -- Amari Cooper's initial impression of Calvin Johnson?
"He's huge," Cooper said. "I can understand why they call him Megatron. He definitely lives up to that."
Literally, and figuratively.
The 6-foot-5, 239-pound Johnson is a guest of the Oakland Raiders in OTAs this week, working with the receivers in an advisory role. And the 6-1, 211-pound Cooper has been bending his ear.
"He just gave me some really good tips on how I can run some of my routes," Cooper said. "He's a different receiver than I am, obviously, but I really admire the way he high-points the ball. And that's something that I try to do as well."
Johnson, who retired in March 2016 after six Pro Bowls, three first-team All-Pro selections, 731 receptions, 11,619 receiving yards and 83 touchdowns in nine seasons with the Detroit Lions, was not made available to the media. He did, however, catch the attention of Oakland's staff when he arrived at the facility as a personal guest of first-year offensive coordinator Todd Downing, who worked with Johnson in Detroit.
"He's obviously a big, good-looking guy," Raiders coach Jack Del Rio said of Johnson. "A couple of the coaches were asking, 'Is he, uh?' No, he's not here to play."
Del Rio laughed.
The coaches were not the only ones at 1220 Harbor Bay Parkway wondering the same thing, even as the Lions retain the 31-year-old Johnson's rights through the 2019 season.
Plus, wistful Raiders fans recall when Oakland selected JaMarcus Russell over Johnson at No. 1 overall in the 2007 draft. The Lions took Johnson second. One scenario then-Raiders coach Lane Kiffin envisioned was Oakland drafting Johnson first, and then taking quarterback Trent Edwards in the second round.
"Calvin's cool, man. I asked Calvin yesterday, I said, 'Hey, Detroit's still got your rights if you, uh, came out of retirement?'" Raiders left tackle Donald Penn said. "He was like, 'Man, they ain't going to let me go nowhere.' But nah, it's good. I seen him over there talking with Coop and [Michael] Crabtree and some of the young guys. Calvin's one of the best that did it so to have him out there picking those guys' brains and giving them advice is great."
The Raiders, it should be noted, acquired running back Marshawn Lynch from the Seattle Seahawks after he came out of retirement. Johnson, though, was scheduled to be with the Raiders for only their first week of OTAs.
And Cooper, who is just the third player in NFL history with at least 1,000 receiving yards and 70 receptions in each of his first two seasons, will be soaking it all in.
"I've just been asking him a whole bunch of questions," Cooper said. "How does he run certain routes? What was his regimen like? How was he so productive? He's a really cool guy. He's been giving me some really good feedback. He's nice to have around."