There's a clarification behind that "out of shape" thing, confirmed by Tim Cato's twit from his last conversation with Luka's trainer. So, it seems there was a misunderstanding with that statement .
According to this twit from Tim Cato:
https://twitter.com/tim_cato/status/1271207910194982915?s=19
And so I look around to see what shape is Luka in. This is what I got from his latest IG story.
Source from his profile: https://instagram.com/lukadoncic?igshid=13kilcler1avn
He looks fine and well. He doesn't look like he lose weight nor he gain either. He looks the same, maybe he maintained his body that very well unlike Harden, and Jokic. They really went into big transformation . Can't wait to see them play with such body .