I've been searching for potential Celtics big men

Y'all didn't like Lucas Noguiera, even though he has long arms, good speed, and can jump through the roof of the gym, in large part because he's only ~"220 pounds" (i.e. real life 250, but small for an NBA big)

Now I present a guy who's projected to go undrafted: Mamadou Diarra

He's 7 feet tall and 285 pounds

On those credentials alone, I'd take him.  Add the fact that he's listed as a good shot blocker, a good rebounder, and a good defender, and you've got our project center of the future!