Well, I just wanted to put the numbers for Williams straight and point out that the Packers wouldn't have to cut Williams to sign Byrd as they could restructure Tramon's contract.
Well, you're correct in stating $7.5 mil vs. $7.3 mil cash cost. But from a practical standpoint the cap differential between keeping vs. dumping Williams is $7.5 mil. We can either pay him and take a $9.5 mil cap hit in 2014 or release him and take a $2 mil dead cap hit. The cap savings is the same as the cash value.
The other possibility is renegotiating Williams as you suggest. However, as illustrated in the Burnett contract, writ larger with Shields, and writ probably a bit larger yet in any Byrd deal, it's "pay me later" with the cap hit and the collectively high risk with dead cap if these players don't play up to their deals.
Any way you cut it, the Burnett contract, the new Shields contract and a Byrd deal would be a lot of future cap and risk concentrated at DB to start with; renegotiating Williams would compound the problem with a 4th., albeit to a lesser degree. It's not like Williams would come dirt cheap anyway.
I would put a Williams renegotiation / extension at a much higher probability than a Byrd signing, but I'd say "neither" would not surprise me in the least. We can carry Williams' $7.5 mil excess cap this year and spend closer to the cap max than otherwise if it is assumed he'll be gone in 2015, yielding a $9.5 cap savings over 2014.
Williams has question marks. Will we get the 2012 Williams or the guy we saw in the closing games of 2013? Was the return to form a sign of recovery from nerve issues in the shoulder or a cap wake up call...a pre-contract year reality check if you will? Further, Williams will be 31 in 2015. I would be very reluctant to make a longish term commitment here which is what Williams would likely be looking for. Offer him a cheap deal and he'll likely play it like a franchise tag year...take the money now and roll the dice in FA next season.