Haircut aside, Justin Herbert's 2020 season went about as well as it could. The No. 6 overall pick in the 2020 draft, the former Oregon quarterback won Offensive Rookie of the Year honors after putting up numbers many veteran quarterbacks have yet to match. In 15 games, Herbert completed 66.6% of his throws for 4,336 yards with 31 touchdowns and just 10 interceptions. He ended his rookie season by leading the Chargers to four consecutive victories. 

The sky appears to be the limit for Herbert and the Chargers, whose over/under for the 2021 season is set at 9 games according to William Hill Sportsbook. One obstacle that may hinder Herbert, however, is the Chargers' turnover in the coaching staff. This offseason, the Chargers replaced head coach Anthony Lynn with Brandon Staley, who most recently was the Rams' defensive coordinator. Los Angeles replaced former offensive coordinator Shane Steichen with Joe Lombardi, whose two years as the Lions' offensive coordinator are sandwiched between two successful runs as the Saints' quarterbacks coach. 

While Herbert may have success inside his new offense, Buccaneers coach Bruce Arians -- whose coaching experience includes time spent with Peyton Manning, Ben Roethlisberger, Andrew Luck, Carson Palmer and Tom Brady -- knows firsthand the challenges associated with young quarterbacks learning new offensive game plans. 

"Worst thing that can happen," Arians recently texted NFL.com's Jim Trotter when asked the impact changing coordinators can have on a quarterback. "Learning NEW isn't ever good."

There are a slew of examples supporting Arians' text. Tim Couch, who worked with Arians in Cleveland in the early 2000s, was a former No. 1 overall pick whose decline was at least partially due to the lack of stability in the Browns' coaching staff. The same could be said of former Steelers quarterback Kordell Stewart, who struggled for several years in Pittsburgh after Chan Gailey left the Steelers to become the Cowboys head coach in 1998. Marcus Mariotta, the No. 2 overall pick in the 2015 draft, also suffered a decline in play after Matt LaFleur -- his third of four offensive coordinators in Tennessee -- left to become the Packers head coach in 2019. 

Even Arians' current quarterback struggled to learn a new playbook upon joining the Buccaneers last spring. Tom Brady, hailed as the greatest quarterback of all-time, recently revealed that his struggles learning the Buccaneers' playbook lasted well into the 2020 season. 

"Midway through the year, I was still trying to figure out how to call the plays," Brady said on the Hodinkee Radio podcast, via JoeBucsFan.com. "I just read [the plays] off my wristband and tried to visualize what was going to happen.

"It's like learning a completely new language. You've spoken English for 20 years and someone goes, 'Hey man, let's speak some Spanish.' And you are like, 'Huh? That makes no sense to my brain.'"

A change in coordinators is not always a bad thing. Troy Aikman flourished in Dallas after Jimmy Johnson replaced Dave Shula with Norv Turner before the start of the 1991 season. Aikman, who posted a 7-19 record during his first two seasons with the Cowboys, led Dallas to an 11-5 record in 1991 and back-to-back Super Bowl wins the following two seasons. Ben Roethlisberger, who was somewhat regarded as a game manager during his first several years in Pittsburgh, reached a new level after Arians became his offensive coordinator in 2007. 

How well a quarterback prepares for his new offenses can help determine his future success. Herbert has already taken steps towards learning Lombardi's offense. He has spoken with Drew Brees, who spent a dozen seasons with Lombardi in New Orleans. Herbert has also reached out to his new center, All-Pro Corey Linsley. He has also begun throwing passes with Keenan Allen and several other teammates in preparation for the upcoming season. 

It also helps that Herbert had different offensive coordinators during his time at Oregon. While change is never easy, it hasn't hindered Herbert's performance in the past, and it shouldn't lead to a drastic drop-off in production now. 

"I think there'll be parts [of the game plan] that are pretty similar but then other parts that are that aren't so similar," Herbert said, via Sports Illustrated. "I think one of the great things that I've had to go through is I've had to go through three or four different offenses, and you've had to kind of find a way to learn and pick them up quickly. I think I've done a good job of that, and hopefully, this year is no different."