I dont know why people mention Marino's last season.
He got hurt with that shoulder/nerve issue which sapped his throwing power and made him leave the game against NE early.
Before that, he was doing fine that season.
He gets rushed back by JJ to play against Dallas on Thanksgiving and his nerve issue was NOT healed. But being the competitor he is, he rushed it and threw 5 ints that day. You could tell he wasn't right yet, but JJ is JJ and he always had a propensity to rush guys back....see OJ MCDUFFIE and his career ending injury.
Marino wasn't quite right but you could see him getting better later on and saw how he was still the man when he got us to defeat the Seahawks that year up in Seattle in the WC round. Of course, JAX the next week was messed up but that was a total team debacle, not one due to Marino or his earlier injury that season.
Marino might not have been the guy from 1994, hell 1984, but he was still a great QB, better than ANYTHING we've had since at 37+ with a messed up shoulder/nerve issue.
Manning will be fine at 35 and having the time to heal like he has. Especially since he wasn't rushed back.