Wrong on both.
If
Benson Mayowa makes the roster next season, he will be paid his base salary of $1.5M in 17 weekly installments.
He will count $2.6M against the salary cap, but that number includes his signing bonus proration of $1.1M.
The entire signing bonus ($3.3M) was paid up front this year when Mayowa agreed to terms and Oakland opted not to match the contract.
For accounting purposes, signing bonuses are divided over the life of the contract (up to five years) because the money is given based upon the expectation the player will fulfill the deal.
If Mayowa gets released, Dallas won't owe him a penny. His 2017 and '18 base salaries will never be paid.
The signing bonus money will still count against the salary cap, it's often referred to as 'dead money' when contracts are discussed, but it isn't money that is owed to the player.
In Mayowa's case, he would count $1.1M against the cap in '17 and '18 if he failed to make the cut following training camp/pre-season.
Dallas would then save $1.035M against the cap next season, that's Mayowa's base salary minus the cost of a minimum salary ($0.465K) player taking his roster spot, and $2.27m in '18.
That's cap savings, the actual cash savings for the team would be $4.25M.
I'm not saying Mayowa is definitely going to come under the axe next summer, it's just a possibility.
He may improve as this season closes and never be in any real danger next year.
We shall see.
The salary cap will not help Mayowa remain on the roster, he has to do that himself.