I've wanting CR with McCoy for ages, let this be the arc. Five and him are natural fits with being generally crabby. We never got to thread him getting patched up, but I'm sure there will be a time when this can come up again. Five is that guy who gets injured and tells no one because he has Stuff To Do and he can take care of it himself, then passes out it happens.

And Marcos is assigned to be his bodyguard when he goes to the Wards, so they obviously should meet. He's generally easy to get along with and happy to be a human flashlight whenever he needs. And you know... if he needs to vent to someone over a drink, he won't stop him.