The Seahawks open the 2016 season at home on Sunday, just the sixth time they've opened at home since 2000, and they do so against the Miami Dolphins, a team they haven't faced since 2012. Not only has it been a long time since these two teams played each other, the Seahawks don't have a lot to go off of when it comes to planning for a Dolphins team playing under a new coaching staff, led by first-year head coach Adam Gase. The mystery surrounding the Dolphins leads our three key matchups for Sunday's season opener.

1. Game planning vs. an unknown opponent.

Usually when studying for an opponent, a team would only need to look at some recent games to have a pretty good idea of how to attack an opposing defense and defend against an opposing offense. But when it comes to the Dolphins, there is no tape, other than preseason games, of what they look like under Gase. The Seahawks can go back to Gase's previous stops as an offensive coordinator in Denver and Chicago, including three games against Seattle dating back to Super Bowl XLVIII, but he is coaching with different personnel now, so inevitably some things will be different.  

"We're looking at everything," Seahawks coach Pete Carroll said. "We go all the way back to the Super Bowl that year and we've looked at everything we can look at. You have the good fortune of the offseason, so we've looked at everything and tried to anticipate, matching up with their personnel and their other coaches that they've added to their staff. That's kind of the puzzle that you work at. It's how we do it, it's a fun kind of study and we'll see what happens."

While there is plenty of film of Gase-called offenses, the challenge might be even bigger for offensive coordinator Darrell Bevell, offensive line coach/assistant head coach Tom Cable, who are game-planning for a defense led by first-time defensive coordinator Vance Joseph.  

"Obviously, they have a new coaching staff, so a little bit of new things for us to look at," Bevell said. "There's not a lot of tape on them, Vance hasn't been a coordinator before so we don't have a lot of tape on what he likes to do. We're looking at all the things we can possibly look at to make sure that we're well prepared to go into this game."

2. Miami's defensive line vs. a new-look Seahawks offensive line.

When Carroll was asked early in the week if it was good for his new-look offensive line to get an early test against Miami's star-studded defensive, he joked, "Well there are some things that may be better than that."

And indeed this is anything but a soft landing for a line featuring new starters at four spots, and possibly playing without starting right guard Germain Ifedi, who is listed as questionable with an ankle injury. The Dolphins have three different four-time Pro Bowlers on their line in Ndamukong Suh, Mario Williams and Cameron Wake, so while Gase noted that his D-line is still finding its chemistry—Williams is new to the team this year and Wake was limited in the preseason while coming back from an Achilles injury—that's still a lot of talent the Seahawks will have to deal with on Sunday.

"They're loaded," Carroll said. "They've got terrific personnel. It's going to be a great challenge for us. Hopefully all the work that our guys have done against our guys will help us. They've got some really notable players up front. Mario, Suh and those guys—they're fantastic players. It'll be a great challenge for us and hopefully we're ready."

Added Bevell: "We have a young group playing together upfront, so that's going to be a big key for us to keep an eye on. Suh and Mario, the names are big names. It will be a good test for us."

Yet for all the star power on Miami's line, the Seahawks kick off this season very excited about the way their offensive line has come together in camp. If Ifedi can't play, that's a setback for now, but the progress shown by Bradley Sowell, Mark Glowinski, Justin Britt, Ifedi and Garry Gilliam has been very encouraging in the eyes of coaches and teammates.

"We're a new group upfront, but we're a talented group that can do a lot of great things, and we showed that this preseason, in my opinion," quarterback Russell Wilson said. "We're all on the same page, Justin Britt is leading the way in his communication and all that. Across the board from left to right, those guys have really been on the same page."

3. Dolphins quarterback Ryan Tannehill vs. Seattle's ability to keep him contained.

Back when Ryan Tannehill and Michael Bennett were teammates at Texas A&M, Tannehill was still a receiver, and he was "the best athlete at our school," Bennett said. "Better than Von (Miller), better than me."

And if you've ever heard Bennett talk about how much he dislikes quarterbacks, you know it really means something when he pays that high of a compliment to one. But while Tannehill is a great athlete, what really makes him dangerous is the way he can make plays with his arm after using his athletic ability to get out of the pocket.

"He's an athletic quarterback with a strong arm," defensive coordinator Kris Richard said. "If his guys aren't open, he has the ability to take off and run, so we know we're going to have to keep this guy bottled up in the pocket, or he's certainly going to represent a challenge as far as running the ball. As far as throwing the football, it's the strength in his arm. He's got good receivers out there, Kenny Stills is a guy that I imagine they'll want to send vertical. He's a deep threat, he's got really good speed. Then Jarvis Landry, he's a really good football player."

Tannehill has enjoyed a good career thus far, but there's optimism in Miami that he will really blossom under Gase, who has built a reputation as being something of a quarterback guru. If that growth manifests itself in Week 1, then the Seahawks defense will have its work cut out for it.  

"Tannehill is a heck of a ball player," defensive end Cliff Avril said. "They have some good players up front. Their running backs are doing some great things. I think all around they have a good offense. For us, we're up for the challenge and we feel like we can definitely compete with them. Again, they're doing some great things. Stop the run and get after the quarterback. That's the goal each and every week and this is no different."