Just for reference sake: Ojeleye was down near the bottom of the team in deflections per 36 (1.3, right next to perennial defensive under-achiever Marcus Morris) for the regular season. He got 40 deflections in the 73 games he played. That's not good. Marcus Smart, who's elite at this, average 3.3. Rozier and Tatum are around 2. We can ho and hum all we want about how Semi moves his feet very well -- and he does! -- but deflections lead to turnovers which lead to very efficient points. Deflections are, on average, a pretty good measure of defense. The guys who lead the league in deflections every year are who's who of elite defenders.
Yes, he's a rookie, but that's not much of an excuse either: Even Abdel Nader got 2.3 (and yes, I'm aware a lot of that is garbage time minutes against garbage players). He's down near the bottom of rookie deflections per 36 too, rubbing lax elbows with defenders of ill repute like Kyle Kuzma and Lauri Markkanen.
The news ain't all bad: my eyes told me he's been slightly more active with his hands these playoffs (certainly not as active as guys like Brown, Tatum, Rozier, and Smart) and that bears out. He's got 7 in 148 minutes (Marcus Smart has 8 in 115). I remember at least one impressive strip on a Giannis drive and another in the first game of this series leaping to deflect a entry pass. I'm aware that there's almost certainly a sample size issue here -- I just don't know how these things stabilize. 148 minutes seems like plenty to me, but I'm not really sure.
So even if there's not terribly much that you can glean from that, it's something to watch over the next however many games.