Prior to his injuries, he was an All-Pro CB.
Why do you say the Ravens failed Marlon?
Marlon should cover the big body or physical WRs or slot.
Ravens also need a legit pass rush. Ojabo and Oweh need to step it up.
Marlon should be exclusively playing slot at this point. He has always played better with the play right in front of him. If he played on a team that played more zone, let him play nickle more, and he could stay healthy, he'd probably be an all pro again. The Ravens play more man than anything.
As far as how the Ravens have failed him. They knew coming out of college that he didn't cover the deep ball well at all and was a liability when asked to do so. They knew he played his best football when the play was in front of him. They rarely put him in position to mitigate his weaknesses, take advantage of strengths or give him help in obvious passing downs. Marlon shoulders some of the blame as well because he knows he can't cover the deep routes and he should've gotten the extra work to not be a liability, but he either didn't or its not working. Either way, the Ravens need to mitigate Humphrey's weaknesses better this season and moving forward if they want him to succeed and produce.
It just seems like the Ravens have expectations on positions, but don't really consider the limitations of their personnel which ultimately hurts the player's production. I will give them credit last season that they considered Stanley's softness and being prone to injuries when they instituted him sharing snaps with Mekari...let's see if that continues this season since an every down top tier LT isn't on the roster. Hopefully this season with the extra CB depth, we see them take Humphrey into consideration more and mitigate his short comings better.