First post! I'm an American living in Australia and I can tell you why Delly plays like his life depends on it day in day out. It's the culture that these Australians have. He aptly put it that Aussies don't like being put on pedestals, and you can see that from the sports they follow.
He played "Australian Rules Football". It's a sport where a massive 18 players per team are on a huge ~700 foot long stadium and no player can individually carry. Big team sport. Because of this, you often get players who post little to no numbers but provide a very important piece of the team puzzle that help them win. I believe Delly gets his game plan from his background in Aussie Rules - he's willing to play ugly, get no recognition as long as it helps the team win.
P.S. I've fallen in love with the sport here, it's the toughest thing I've ever seen. This is where Delly gets his hustle and grit from. Check out some of these insane hits this sport has. The players aren't beefcakes who can take hits - they're built for endurance, yet they dish out huge hits with no padding. Massive respect.
EDIT: How do I embed a video? Can someone do it for me on the link below?
https://youtu.be/s1aU0hz5Tf8