I don't know that Seljaas has the physical quickness to be a really good one on one defender. However, I believe he is a pure wing and should not be played at the 4. This is especially true given that 6 of our schollie guys on this roster are already 4/5s. If the coaches really believed we were so thin at the 4 that we need Seljaas there, then why keep guys like Shaw, Nixon, Andrus, Worthington, etc. on scholarship. So just based on the allocated spots on the roster, I don't believe the small ball predictions of Seljaas at the 4.
Then, as a wing, Seljaas needs to just be a smart team defender who tries hard. I do think that Ingles from the Jazz is a good comparison. He is a well below average athlete with limited lateral quickness. But, he was a really good defender last year because he understood scouting reports, team positioning and defensive rotations and he tried really hard. He used his length really well. Seljaas absolutely can be that guy.
IF, the roster composition does change, Gavin Baxter seems to be a guy with the strength and explosiveness to play a stretch 4. I believe he is a legit 6'8" with length and a ton of explosiveness. I could see Coach Rose showing a couple more guys the door as Worthington and Shaw have both had multiple years and not yet proven they belong at this level. But, for this year, I am confident with a big man rotation of Childs, Dastrup, and Andrus. I believe Nixon, Shaw and Worthington will all get spot duty based on matchups and foul trouble. Nixon also may really only have this 1 season to prove he can play at this level.