PHILADELPHIA -- The handshake was going to finish with Philadelphia Eagles coach Nick Sirianni playing air guitar. That much was certain.

It was early in training camp and there was a rare lull during practice, and Sirianni and quarterback Jalen Hurts used that time to work out a personalized handshake. They went through their sequence of coordinated slaps and backhands, slaps and backhands, and each time they got to the end, the ever-animated Sirianni started acting like he was Jack White in the middle of an epic solo. Hurts, the more laid-back of the two, wasn't going there. He just smiled and laughed.

It was a brief interaction and far from a big deal in the grand scheme of things, but it stood out given what was happening at the time. Sirianni had not publicly committed to Hurts as the Eagles' starter for 2021. The trade speculation surrounding the Eagles and Houston Texans quarterback Deshaun Watson was at its height. And it wasn't long after Sirianni gave an honest public assessment of Hurts' footwork, saying "the process [of addressing those fundamentals] is going well, but we are far from where we need to be."

It was a small sign the relationship wasn't being negatively impacted by its first stress test. But things are going to ratchet up in a big way starting Sunday when the Eagles open the regular season on the road against the Atlanta Falcons (1 p.m. ET, Fox).

The coach and quarterback relationship is as important as any on a football team. It is also extremely pressurized, especially in a city like Philadelphia where a loss is an affront to the fan base, making it only natural to put the primary suspects -- the coach and QB -- on trial.

Sirianni, a first-year head coach, and Hurts, who enters a season as QB1 for the first time, have been working to strengthen their bond to prepare for the rigors that lie ahead.

"It's important that we don't just have a football relationship," Sirianni said. "That's important for me with every player on our team, that I have more than a surface-level relationship with our players. There is more to it. That's connecting on different things."

College football is one way to do it. Sirianni said he texts Hurts after both of his college teams, Alabama and Oklahoma, finish their games. "He's got two teams I can razz him about," Sirianni joked, before quickly acknowledging there's little he can ding the powerhouse Crimson Tide on.

Sirianni and Hurts each come from a football family. Both have fathers and brothers who are coaches, which has become a source of common ground.

"We've built a great relationship in such a short time," Hurts said. "We're very similar in many ways. Very competitive. Have a sense of humor. Just cool people. He's a good guy."

Sirianni noted with a smile that the coach and quarterback "have no choice but to grow closer" given all the time they spend together. Sirianni is a hands-on coach, feeling the need to be in every offensive meeting in order to have a full and clear picture as the Eagles' playcaller. From watching film to game-planning, they're often attached at the hip.

Tailoring the offense has been a collaborative approach. Sirianni said he won't install a play Hurts isn't comfortable with, even if the rest of the coaching staff loves it.

What the offense will look like is a bit of a mystery. So is the future of the Eagles' coach/quarterback tandem. This isn't a situation in which Hurts, the team's second-round draft pick in 2020, is the no-doubt-about-it franchise quarterback. It is to be determined whether he and Sirianni will be together long term or if this is a temporary arrangement.

But the fates of coach and quarterback are often tied together, making it all the more important for both to have a strong connection. You can scroll through the NFL annals for proof of that, or just look at what happened last year in Philadelphia with coach Doug Pederson and QB Carson Wentz.

When things got messy last season, the parties began pulling in different directions and the operation fell apart.

Things will get messy again -- they always do in the NFL -- and that will be when we really learn about the strength of the bond between Sirianni and Hurts. But there has been an attempt to lay a foundation before that time comes, and there's something to be said for that.