4. Nick Sirianni
Speaking of Philadelphia Eagles' coaches, Nick Sirianni also spent time on the Chargers coaching staff before he led his team to the Super Bowl last season. Sirianni is considered one of the best young coaches in the league and if he can repeat last season's success then he will continue his ascension.
The path for Sirianni being the head coach for the Chargers is not as clear as others on this list. However, he still spent time in the Chargers coaching staff and the team could have done more to keep him around.
Like Reich, Sirianni joined the Chargers coaching staff in 2013 when Mike McCoy took over as the head coach. After one year of being an offensive quality control coach, Sirianni was promoted to quarterbacks coach when Reich was promoted to offensive coordinator.
Sirianni lasted longer with the Chargers than Reich as he transitioned to being the wide receivers coach for the 2016 and 2017 seasons. After 2017, Reich hired Sirianni to be his offensive coordinator in Indianapolis, paving the way for him to eventually become the Eagles head coach.
The Chargers didn't even interview Sirianni in 2021.