In news first reported by ESPN’s Jeremy Fowler, the Carolina Panthers are expected to hire former Texans assistant Sean Ryan as their new quarterbacks coach.
Ryan, who spent the last two seasons in the same capacity with the Lions, will replace former Panthers QB coach Jake Peetz, who recently left Carolina to accept the offensive coordinator position at LSU.
A 13-year NFL coaching veteran, Ryan spent nine seasons with the New York Giants, fulfulling a number of roles (quality control, WR and QB coach) while collecting a pair of Super Bowl rings. Panthers coach Matt Rhule was an offensive line assistant on the same staff as Ryan in 2012, prompting speculation that Ryan would land the offensive coordinator role on Rhule’s inagural Panthers staff in 2020. (Joe Brady eventually got the gig.)

The headline mentions the Texans. I don’t think you need an explanation as to why.
Ryan was Deshaun Watson’s first NFL QB coach, and was instrumental in Watson’s early pro development from 2017-18.
“Ryan and Watson communicated clearly and got along well, collaborating adeptly as the former college national champion emerged as a Pro Bowl addition during an AFC South division championship season in 2018,” wrote Texans reporter Aaron Wilson in 2019.
In Watson’s two seasons with Ryan by his side, the production was remarkable:

Ryan’s hire becomes notable for a number of reasons, including the uncertain status of current OC Joe Brady. Should Brady land a head coaching gig in the next 12 months, Ryan would be a prudent option to fill from within.
It’s also worth examining the timing: Carolina has now been linked to Deshaun Watson, who will likely seek a trade after a fallout with Houston management, by both NFL Media’s Ian Rapoport and ESPN’s Jeremy Fowler, among others. Ryan and Watson shared a notoriously solid working relationship in Houston.
While Ryan is worth consideration on his own merits, this hire could serve as a signal from owner David Tepper to Watson, a star QB who has felt alienated and marginalized of late in terms of staffing decisions.
As outlined by Aaron Reiss from The Athletic, the Watson/Ryan dynamic is hard to ignore–on a day-to-day level, Watson and Ryan worked in harmony as much as any two people in the facility:
So why did he leave Watson and the Texans?
The buzz on that: Ryan reportedly didn’t see a viable path for play-calling duties under since-fired Bill O’Brien, via Reiss. Ryan subsequently interviewed with the Browns for their OC vacancy–Cleveland settled on Todd Monken.
With Joe Brady’s stay in Carolina expected to be brief, it’s a great opportunity for Ryan to get in the door with Rhule before the OC chair becomes officially vacant.

Deshaun Watson may never play a single snap in the Carolina black & blue. But with the hiring of his inaugural QB coach, as well as the owner’s endless resources + a publicly-stated desire to elevate their quarterback situation, the possibility simply can’t be ignored.
Ryan is one more context clue. Nothing more. Nothing less.