They will be cheaper players available at cut downs, or maybe sooner once replacements are secured in the draft, to fill out the bottom of the roster. There are several guys who have been around for a couple years who are "just guys" or worse who could be upgraded.
The only other possibility that would allow buying somebody more pricey would be a surprise cut of somebody who would yield some meaningful cap space or somebody getting negotiated down for 2016. See the "cap savings" column in the following link; that tells you the cap amount picked up if the guy was cut, or one can look at the actual cap numbers to identify situations where it could be worked down for 2016 in a renegotiation/extension:
http://overthecap.com/salary-cap/green-bay-packers/
Frankly, I don't see any obvious opportunities or likely candidates. Does anybody think Thompson will slap Peppers in the face proposing a worked down one year deal? He'd have to extend him at least another year to get it to work without being an insult. I don't think that will happen. Or how about jumping the gun a year and cut Sitton to pick up cap room? I don't think so.
One possibility is if Sitton or Lang or both (more likely just Lang) is extended now with the last year in the current deal rewritten with a low base salary and a big signing bonus, back loading the cap hit to future years. You could a pick up a couple of mil for this year.
Note we're at $148 mil for the top 51, not including Starks who is not yet added to that list.
Still to do:
1) You have to add a couple mil for the upper round picks getting paid more than the bottom of the roster guys they replace.
2) In addition to Starks, you have to add in one additional guy not in the current top 51 to get to the 53 man roster. Call it about a half mil for minimum salary rookie.
3) You need about $1 mil for the practice squad.
4) You need about $3 mil minimum in reserve for replacements for guys who go on IR. And that only buys about 6 - 7 minimum salary rookie replacements.
5) Whatever is left over can carry over to 2017.
I hate to say I told you so (actually not so much), but I illustrated a year ago why 2017 free agency would be a pinch, but I don't recall one single note of agreement at the time.
The bailout would be if the cap is going up more appreciably than to the $155 mil commonly projected. Then again, when the cap goes up so does salary inflation...as we see in recent Crosby, Perry and Starks deals.