In regards to Matthews:

There are two years left on his contract.
His 2017 salary will be $15.2M (with $4.1M in dead cap).
His 2018 salary will be $11.4M with no dead cap money.

He will be 31 this next season. I saw on ESPN, that Matthews is one of the 4 highest paid LB's in the NFL (this came up on the Jamie Collins LB Browns, who just signed a new contract).

I think the Packers should let it ride for 2017, but all bets are off for 2018 depending on his performance (and health) this next season.