It's Rozier, and *maybe* Brown.
Rozier considers himself a 30 mpg player and he's only hit that mark twice in 18 games. Averaging 19 mpg over the last 4. Playing for a contract. Obviously unhappy.
Brown is the wildcard here. The team has elevated both Tatum and Hayward ahead of him, despite him having a year on Tatum and Hayward obviously not 100%. Over the last 5 games Tatum and Hayward are playing 30+ and Brown is averaging 24. I think he considers himself a rising All-Star but he's being treated like the 5th wheel behind Irving, Hayward, Tatum and Horford and on par with Rozier and Smart. That's 7 guys around or above his level with no end in sight.
I see the proper roster as:
The core: Irving, Hayward, Horford
The untouchable future star: Tatum
The blue collar guys: Smart, Morris, Wanamaker, Baynes, Theis
The cancer: Rozier
The assets: Brown, SAC19, other 1st rounders
Prospects: Williams
Sorta useful: Ojeleye
Expendable: Yabusele