NASHVILLE, Tenn. -- Back in 2015, Ken Whisenhunt was supposed to be the buffer for No. 2 overall pick Marcus Mariota's transition from Heisman Trophy winner at Oregon to the Tennessee Titans' franchise quarterback. Instead, the Titans decided to move on from Whisenhunt after the team's abysmal 1-6 start during Mariota's rookie season.
Whisenhunt was on a short leash after Tennessee finished the 2014 season 2-14, which put them in position to select Mariota near the top of the 2015 draft. After being fired by Tennessee, Whisenhunt was rehired as the offensive coordinator for the Los Angeles Chargers -- the position he held before signing a five-year contract with the Titans in 2014.
Whisenhunt had found success with traditional pocket passers such as Ben Roethlisberger, Kurt Warner and Philip Rivers. Mariota didn't exactly fit the same mold, but the Titans' brass -- including Whisenhunt -- were intrigued by how the young QB made so many dynamic plays in college. Although things didn't work out for Whisenhunt in Tennessee, Mariota is thankful the coach signed off on bringing him to Nashville.
"I just appreciate the fact that he, alongside of Ruston Webster who was here, took a chance on me," Mariota said. "I was sort of that spread quarterback that didn't really fit the prototypical NFL quarterback. They gave me a chance, and I'm forever grateful. I think [Whisenhunt] knows that. I look forward to seeing him."
Sunday's game in London (9:30 a.m. ET, CBS) will be Whisenhunt's latest chance to face the team that fired him. The Chargers' offense is red hot, averaging 412.5 yards per game, seventh in the NFL, and Rivers has 15 touchdown passes.
There is no doubt that Whisenhunt will want to flex his muscles against his former team the same way he did in 2016, when his Chargers scored 43 points against Tennessee. The Chargers are likely to test the Titans with deep passes from Rivers to wide receivers Tyrell Williams and Mike Williams. Whisenhunt's scheme gives the talented wideouts opportunities to make plays down the field.
"When you look at every 'X' play around the league, you find out about 70 percent of them are players and 30 percent of them are the scheme," Titans coach Mike Vrabel said. "A guy gets wide-open, or they got kind of a little rub route, or they knew what the coverage was, and they ran something that took advantage of it. The other 70 is a guy going to make a play, a receiver that jumps up and catches the ball over somebody, a quarterback throwing into a tight window. That's what it comes down to in this league: 70 percent of the time they launch it down there, and [Tyrell] Williams made a play on somebody."
One player to watch Sunday is Titans cornerback Malcolm Butler, who is expected to be heavily targeted by the Chargers. Butler matches up better against bigger wideouts (such as the Williams duo) whom he can get his hands on at the line of scrimmage. Given how Rivers is a pure pocket passer, Butler and the Titans secondary can benefit from disruptive interior defensive lineman Jurrell Casey collapsing the pocket from the inside.
Penetration by Casey is one key for Tennessee because he can make it more difficult for Rivers to step into his downfield throws. Another key for the Titans is safety Kevin Byard, who will be called upon to help in deep coverage.
However, the Chargers are more than just Rivers and the passing game. Running back Melvin Gordon has 466 rushing yards, which ranks third in the NFL. He is averaging 5.1 yards per carry and has rushed for six touchdowns through six games. By comparison, the sputtering Titans offense has scored only five touchdowns in that span.
The Titans' defense has struggled against the run at times this season, allowing 123 rushing yards in a 21-0 loss to Baltimore (Week 6) and 144 against Buffalo in a 13-12 loss (Week 5). Tennessee's linebackers will have to maintain gap integrity Sunday because Gordon is the kind of dynamic back who can take it the distance if he gets a crease. He has four runs of 20 or more yards already.
Tennessee won't have outside linebacker Derrick Morgan, so Kamalei Correa and Harold Landry will have to step up in Morgan's place. Their job will be to funnel running plays back inside for linebackers Rashaan Evans, Jayon Brown and Wesley Woodyard.
Containing the Chargers' explosive offense will be a tall order for the Titans, especially with Whisenhunt having his foot on the gas trying to make the flight home from London a long one for his former employers.