This will get worked out at some point.
It's clear the Patriots want protection against undisclosed injuries and that Jacas, based on recent workouts posted, is saying they don't need it, he's fine.
He doesn't want to participate, injure something, and lose his money if an injury happens. Pats don't want to guarantee against an injury for something they were unaware of.
Jacas has way more to lose than the Pats by signing a contract without injury protection, be interesting how they end up compromising but there is no benefit to either to not get it done.
To me it's a catch-22: If the guy played with a knee issue, a hamstring issue, a torn labrum shoulder and a foot stress fracture and is now healthy, then he should be much better than his tape which was already good. If some of those happened after the season and are a sign of a guy already breaking down, then not so good.