Potential paths:
Djokovic (1):
2R: Paul
3R: Auger-Aliassime
QF: Shapovalov / Goffin (leaning towards Goffin)
SF: Medvedev
F: Thiem / Zverev / Tsitsipas (Tsitsipas most likely)
Thiem (2):
2R: Krajinovic
3R: Dimitrov
QF: Zverev / Murray
SF: Tsitsipas
F: Djokovic / Medvedev
Medvedev (3):
2R: Qualifier
3R: Fritz / Garin
QF: Khachanov / RBA
SF: Djokovic
F: Thiem / Zverev / Tsitsipas
Tsitsipas (4):
2R: Anderson
3R: Isner
QF: Berrettini / Schwartzman
SF: Thiem / Zverev
F: Djokovic / Medvedev
Lotta next-genners in Djokovic's side of the draw, and of course he'll have to be careful if Medvedev makes it to the semis. Med's projected draw looks to be the softest of the top four seeds so I think he could reach the semis without many problems. That is, if he returns to form and doesn't mug things up like he did post-Shanghai last year.
Tsitsipas could fall victim to an upset in the early rounds given he may first play Isner and Anderson. He'll have to start sharp (especially on the return) or he may find himself out of the tournament. If he makes it far enough to meet Thiem, I'd back him.
Thiem has a somewhat challenging draw, but if he brings the form that he brought during his previous few hard court tournaments (such as the ATP Finals and the AO) he could surely manage. Zverev may prove dangerous for him...
Seems like some things are falling in line for another next-gen triumph at Cincy, but Djokovic still remains the favorite. Can't wait to see how it plays out.