With Horford and Marcus Morris gone, I could see Grant Williams as being the 1st guy off the bench by Spring 2020.
Gordon Hayward is going to have a cap on his minutes AND the per 36 minutes stats of Hayward's back ups are underwhleming.
Guerschon Yabusele 13.5 points 8 boards
Semi Ojeleye - 11 points 5 boards
Daniel Theis is a bit more productive than that but he'll have to back up at Center until Robert Williams develops.
Is it me or does Grant seem really undersized and a bit slow? Having said that I should say that doesn't mean he hasn't played great or that I don't think he'll be a great player. He's so gritty and well-rounded that he's hard not to like.