How far can Gruden, Carr go?
Carr hasn't had the opportunity to play for a coach like Gruden, an offensive mastermind known for his maniacal work ethic and attention to detail.
The way those two fare together will determine whether Gruden's return for a second stint as coach of the Oakland Raiders will end up as the resounding success owner Mark Davis hoped for while pining for a reunion the past six years.
"I had a chance to visit with Derek Carr this morning and I said, 'Derek, this is an unbelievable opportunity and if you'll just take advantage of the opportunity, there's so many great things in store for you, not only professionally but personally,'" said Rich Gannon, whose career took off after joining Gruden in Oakland in 1999.
"Jon's excited to work with Derek and Derek's already a good player but he's got a chance to be a Hall of Famer and win multiple Super Bowls if he'll just do the work."
Carr will be tested and challenged like he hasn't in his first four seasons. Gruden is famous for arriving at work each day at 3:17 a.m., putting in long hours each week.
He will also ride Carr hard if necessary in order to bring out the best in his game.
"I don't care how hard Derek worked before, he's going to have to change his work habits a little bit to fit in," Gannon said.
Gannon became a star when he joined up with Gruden after 12 seasons as a journeyman in Minnesota, Washington and Kansas City. He became a first-team All-Pro in his second season with Gruden and won the league MVP the year after Gruden was traded to Tampa Bay.
Carr showed he was capable of being a top quarterback when he garnered MVP support in a breakthrough 2016 season. But he took a major step back this past year after signing a $125 million, five-year extension.
He matched his career high with 13 interceptions and recorded his worst totals in yards, touchdown and passer rating since his rookie year in 2014.
"I think there is a huge ceiling in Derek Carr," Gruden said. "I think he has proven that. Up to us as a coaching staff to improve around him, get more consistent, and come up with an offense that really allows him to soar into another level."
Fixing Carr is just one of Gruden's tasks. Getting receiver Amari Cooper back on track is nearly as important. After beginning his career with back-to-back 1,000-yard seasons, Cooper took a major step back in 2017. He was plagued by the drops that hurt him as a rookie and only topped the 100-yard mark twice all season while finishing with career lows with 48 catches for 680 yards.
It was a puzzling drop-off for a receiver who entered the year considered one of the top in the game. Hall of Famer Tim Brown said he believes Cooper could be in for a 120-catch season if he listens to Gruden's advice.
"Even for a guy like me, who was having a pretty good career, he was able to take me to another level, showing me how much better I could be," Brown said. "I thought I was doing pretty good. Sometimes you just have to turn your brain off and buy in. If you can do that great things can happen."
Even some of the greatest players in the game's history credit Gruden for some of their success. Hall of Famer Jerry Rice arrived in Oakland in 2001 as the most accomplished receiver in NFL history but appeared to be on the decline after failing to reach 1,000 yards in each of his final two seasons in San Francisco.
But he had a rebirth in Oakland under Gruden, catching 83 passes for 1,139 yards at age 39. He followed that up with 92 catches for 1,211 yards the following season and compared Gruden to his former coach in San Francisco, Bill Walsh.
"Could be your best friend or your worst enemy, that's going to keep you on your toes," he said. "Maybe that was something that the players, they were lacking this year. Sometimes you fall into listening to the talk but you need a coach that's going to keep you focused. With Jon Gruden, he's that type of coach."
While Gruden's biggest impact is on offense, his leadership and intensity translate to the entire team. Hall of Famer Howie Long has seen just about everything. He played for 13 years, announced for more than two decades and has two sons in the NFL.
So Long knows what players want in a coach.
"They want to be great and they want to be led," he said. "They want to believe in the guy in front of the room. I call it the Saran Wrap factor. Players see right through that in the front of the room if you're not authentic, you're not genuine, you're not that way every day. ... Jon has that."
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