Diarra will be our most important piece if he returns. I don't understand how posters suggest an unproven/untested D1 freshman will be instantly better than a 5 year, 2 time Champion, BE 6th man of the year winner who has years of D1 experience, including some BE.
He knows Hurley's system, he's a proven leader and is the perfect player to help train Nowell and get him up to speed. Diarra doesn't need to be an NBA prospect, he just has to continue being a very good collegiate guard.
I remember Boatright recruit where people felt he was going to start over Bazz. There are other highly prized recruits that didn't start as a freshman, including our most recent 7'2" NBA prospect.
I'm not saying that Diarra will end the season as the starting guard, but I would bet a lot of money on him starting in November and running Hurley's offense which he knows very well. I also don't think he's returning to be on the bench in November.
Just saying freshman are freshman, at least until February and I won't make the mistake of overestimating incoming freshmen contributions.