Definitely hurts the depth at the 2 spot. Both he and Blackshear were expected to get a lot of minutes behind Kuric, who although a great shooter, is not going to be a guy who can drive/draw fouls, etc.
I guess they can try to put Chris Smith there, or FR. Nunez, but I think Marra was one of those smart players who doesn't excel at anything, but who knows the system and can be counted on to score some points every few games or so.
He was also a pretty good free throw shooter, at almost 80% ))
Lville plays such a frantic style of play (their D is really a thing of beauty given they have no real NBA guys minus maybe Siva) they really need every one of the 60 players they have on their roster this year.