Must have been pretty healthy based upon the base salary of that contract. No team is throwing around that kind of money if the player isn't in decent shape
He already had the contract. What we're talking about here is the extra bonus money they gave him a chance to earn because by that point the long term deal he'd signed way back when was like 4th or 5th highest for the position. The guaranteed money was also long gone by then, and with football, a contract is really only worth the guarantee. So instead of simply paying him a few extra bones, they made it so he had to stay healthy and earn it, something which he hadn't done since his second year in the league, which was the last season he played all 16 games.
They did this with Brady around the same time too, after he was also being paid significantly less than what he was worth and what the top QBs were making.
And this is a same church different pew kind of scenario with Stefan Gillmore right now. He wanted more to play last year, so they converted money from this year and gave it to him early. Problem is, they now expect him to play for just the remainder of what wasn't converted early, and he basically refused and played up an injury so they can't fine him for holding out. At the end of the day, they outplayed their deals, and they want to be compensated fairly but the Pats always have to leverage someone whenever they want. Which is dumb, because they certainly didn't like it when Welker did it to them.