Gronkowski hasn't returned yet. Romo had a herniated lumbar disc, and one could even say that after that he wasn't as good. Peyton Manning had a herniated disc in his neck and had surgery just like Letang is about to. Peyton Manning was a complete shell of his former self.
Peyton Manning on his neck surgeries rehab — and how he almost didn’t make it back
I'm not saying Letang won't make it back, but I put this one right up there with the stroke.
Manning had cervical fusion surgery, then re-injured the disc, I believe. He ended up having three neck surgeries in an 18 month span, then the fourth and final neck surgery.
He dealt with these setbacks and surgeries when he was 35 I believe? Then came back with Denver the following year and had a very good season, then his second year in Denver he put up his best statistical season ever, which is saying something considering his video game stats, when he was 37... almost 5500 yards and 55 td.
He had another great season the following year at 38, and then finally slowed down and had a gum band arm at 39, which is pretty common for most QBs that age.
Manning's neck injury was pretty brutal so, there is a lot of hope here for Letang IMHO.