Will it be marcus morris getting his shot or playing with second team
I'm betting he starts, at least at the beginning of the year. I just don't think that Horford/Baynes or Horford/Crowder is workable in the starting lineup, and Tatum won't be ready.
will it be the horford- hayward duo with its better passing than avery and haywards ball handling that combine to be even better than the parts
Good point, and in fact add Jaylen Brown to that. The ball is going to move.
Jaylen as a starter and add his defense
I agree that Jaylen will be a starter - he's the real replacement for Bradley, in fact; Brad had him guarding ballhandlers last season, as well as wings.
Rozier and a further year and summer season workouts
Of the 2015 draft class, it was only Rozier who stepped up into the rotation last season. And his 2017 playoff performance was a very pleasant surprise. Still, he's got more competition now that wings will have the ball more. Crowder and Bradley were outstanding spot-up shooters, but neither was getting the ball to create offense.
Could semi step ahead of yabusele because of defence
I'd like to be the one to say that Semi is the player "who will surprise", and I do think that he'll get some burn in February or so. Like you, I love his defense - great laterals and anticipation, keeps his arms up, quick shoulders, stays vertical, good strength to check bigger guys, good feet and fundamentals - but you'd have to slot him behind Morris and Tatum at least; so his competition with Yabusele and perhaps Theis is for the third swing, not the backup.
Could Nader nail his threes
Maybe, but he's on a team with a sudden glut of triple-threat wings. I'd predict that he'll get more DNP-CD's than made threes this year.
or will it be all around Tatum
Given what we saw last year with Jaylen, it's likely that Brad will give Tatum minutes early and often. Mostly, I'd predict, the results will be treated by fans and media as a confirmation rather than a surprise. Whatever his "ceiling", Jayson Tatum is the closest thing to a sure thing among recent Celtics' draft picks.