Throughout a nine-season NFL career, Ron Rivera saw a great many things as a Chicago Bears linebacker, including one of the most memorable Super Bowl runs in NFL chronicle.
"Riverboat Ron" also coached in a Super Bowl when he helmed the Carolina Panthers.
For all that Rivera's seen, it's a second-year quarterback with speed in his step and snap in his arm that makes the veteran coach and former player apprehensive.
"He's such an elusive guy, he gives me anxiety," Rivera told reporters on Wednesday of Arizona Cardinals dynamo Kyler Murray, who will face Rivera's Washington Football Team on Sunday.
The reigning AP Offensive Player of the Year, Murray is hot on the heels of leading the Cardinals (1-0) to one of Week 1's biggest upsets when Arizona downed the reigning NFC champion San Francisco 49ers. Rivera's Washington debut also saw a big upset as his squad upended the Philadelphia Eagles.
But it's on to another flock and a Cardinal named Kyler that's difficult to prepare for with Murray's dual-threat ability accentuated by Arizona's wide-open offense.
Murray will face a first-round-laden front for a second week, going from the Nick Bosa-led 49ers to Chase Young-led Washington. But the mighty Murray did it all against San Fran, tossing for 230 yards and a touchdown and rushing for a game-high 91 yards and another score. Therein lies the reasoning for Rivera's anxiety.
"You guys saw it Sunday," Rivera said, via the Arizona Republic. "Shoot, he's a dynamic player, he really is. He's got terrific athleticism, gets outside the pocket and extends plays. He's got great vision and anticipation and he delivers a great football."
However, these aren't the first sleepless nights for Rivera caused by Murray.
During Rivera's ill-fated final campaign last year in Carolina, Rivera and the Panthers' first win of a five-victory season came against Murray and the Cards. Murray was held to 173 yards passing, tossed a pair of picks and was sacked eight times.
Perhaps the anxiety is mutual.