Whenever a player "breaks out," there are massive implications for their team, often psychologically and emotionally. Sometimes a player performing better than expected can rejuvenate a team, inspire them to reach higher, and create a shift in locker room culture. However, from an ownership and financial management perspective, there are even deeper ripple effects.
The NFL's salary cap, at its core function, pushes teams toward mediocrity. When teams experience success, players demand increased compensation. With limited spending, teams are forced to choose between which players to keep - allowing some of their other good players to be signed by other teams in free agency.
Although mostly optimistic, fans aren't totally sold on Rawls - and that's okay. He's had several big games but hasn't been able to prove himself over a long period of time. For the purpose of this discussion, let's assume Thomas Rawls is a serviceable running back for the foreseeable future - in fact, let's assume Rawls is a successful replacement to Lynch. I'm not saying he is or will be - but let's assume it for a second.
Rawls, after spending time at Michigan and Central Michigan in college, went undrafted and is subsequently a rookie undrafted free-agent. He was initially project as a mid-round pick, but was overlooked by NFL scouts for previous baggage in college. However, the Seattle scouts took a risk on him. The Seahawks signed Rawls in May 18, 2015 to a three year deal worth $1.6M. At the time, Turbin and Michael were still on the roster - so Rawls was listed as the fourth runningback on the depth chart.
Seattle controls Rawls for incredibly cheap through 2017. His highest cap hit is $620,000 in 2017 - essentially a few pennies in the grand scheme of things. When signing with Seattle in May, Rawls received a $15,000 signing bonus. (Numbers and Graphics per OTC)
If Rawls continues to produce at a high level, it will give Seattle the option to consider moving on from Lynch and spending much-needed draft capital and cap spending to fill other holes in the roster - most notably the offensive line. Now, let's take a look at Lynch's contract.
In 2016, Lynch will have an $11.5M cap hit - barely edging Adrian Peterson for the highest 2016 cap hit among running backs. The difference in cap hits between the two in 2016 is $11M. Now, if the Seahawks were to cut Lynch (or if he retired) in 2016, the Seahawks would save $6.5M and take a $5M dead money hit due to his signing bonus proration. If Lynch were to retire, Seattle would have the option to go after that signing bonus. But with the respect this front office has for Lynch - I don't see them doing that if he did choose to retire.
Assuming Lynch is gone and Rawls named the starter, an extra $6.5M in cap space will give Seattle the chance to start building a line (through free agency and the draft) around Russell Wilson - while also fielding a dangerous running back. Simply put - the production difference (the drop off) from Lynch to Rawls might not be worth the $6.5M cap difference. This leaves Pete and John with an interesting decision.
A $6.5M cap difference in 2016 and a $12M cap difference in 2017 is notable. This extra money could be used to sign O-linemen in free agency, re-sign Russell Okung, Bruce Irvin, Jeremy Lane, or other position holes in the roster. I'm not saying this is what the Seahawks should definitively do - but it's important to understand how the Seahawks can free up a big amount of extra space with a simple move like this. Again, this is all assuming Rawls is the real deal.
Let's say Lynch and Cary Williams aren't here next year. With those two not on the roster in 2016, I have the Seahawks at a projected cap space of $33,745,942 before contract extensions (assuming a $150M cap - and I think it'll be higher than that). Much of that money will be used to re-sign players - but I believe Seattle has the cap flexibility and cap space to field a competitive team for a long time. Brian Nemhauser published a cool graphic a while back showing which players need to be re-signed and which players still have a few years left on their contract.
Hopefully this helps you visualize what the Seahawks need to do. Lane (who no one is talking about - is on the last year of his deal), Sweezy, Okung, Bruce - there's players Seattle will decide to re-sign and players they'll undoubtedly add.