Sean O'Mara and Trevon Bluiett were essentially equal in terms of offensive efficiency last year. There are, of course, some massive caveats to that statement, but it's worth noting that Xavier's foul machine of a freshman was actually quite effective in the time that he played. That the time he played was 106 minutes is the major caveat to his offensive efficiency and a testament to just how very much he enjoys bodily contact while playing the sport of basketball. Only Jalen Reynolds fouled opponents at a higher rate last year; no Musketeers drew fouls at a higher rate.
That leaves us with a somewhat imperfect but relatively accurate portrayal of O'Mara as something of a blunt impact weapon on Xavier's frontline. Like Reynolds and James Farr, his offensive rebound rate hovered around the 11% mark. In fitting with the idea of an unrefined player though, Sean grabbed defensive rebounds at a 9% rate, lower than that of Myles Davis. The same reckless abandon that gets offensive boards can occasionally lead to positioning mistakes on the other end. A summer of work can be expected to clear some of that up.
Best case scenario:
O'Mara is both blessed and cursed with the teammates he has. He's simply not going to supplant Farr or Reynolds in the starting lineup because he isn't as explosive as either. He is, however, a delightfully brutal change of pace to both of them. If things work out well, O'Mara finds himself first off the bench to replace either and plays 15+ minutes per game, turning the opportunity to throw his body around into a lot of second chance points and possessions kept alive.
Worst case scenario:
Sean keeps fouling everyone he sees. Only one time against legitimate competition last year did O'Mara play double digit minutes and not commit two or more fouls. In that game against Alabama he went for 8/2/0. (He was also effective and not foul prone against Murray St.) If he stays out of foul trouble, he's going to get the job done. Unfortunately he averaged six fouls per 40 minutes he played. If that is the case again this year, expect something along the lines of 106 minutes of court time again.
Most likely scenario:
This is a cop-out, but right smack in the middle of the two above scenarios. O'Mara can play the game when he doesn't foul, and it's fair to expect him to be better this year. What isn't fair is to expect him to completely lose the urge to hack. Expect to see the minutes per game to rise to nearly 10 and O'Mara to tantalize with flashes of real game. The freshman showed last year why he landed with a program like Xavier. He'll take another step forward in this season.