But "Delly", the 22-year-old who started in the point guard role for Australia at the London Olympics last year, simply did what he always does, working his butt off on the training track to prove the disbelievers wrong.
Right now he has an invitation back to the Cleveland Cavaliers pre-season camp in October and it's not a "find your own way over and we'll take a look at you" but a genuine shot at a roster spot with the rebuilding franchise.
"Cleveland is looking for a third point guard and I have a shot at it," Dellavedova said today.
I would agree with Dellavedova. There is a very good opportunity here for him to make the roster as the third point guard. Given Kyrie Irving's injury history over the past three seasons (including his freshman season at Duke), it probably makes sense to go into the season carrying three. Dellavedova is as good a candidate as any to hold that third point guard job on a minimum contract.
It's also worth noting that even though Dellavedova's numbers didn't particularly impress fans at summer league, his play and particular focus on defense apparently did.
He worked hard for new coach Mike Brown at the Cavaliers' camp, and enjoyed a very solid NBA Summer League with the team in Las Vegas.
"I thought I did OK," he said of the experience.
"I played my role pretty well, trying to get other people shots."
But Dellavedova knew full well NBA scouts were observing him with a critical eye, mindful of his allegedly suspect defence.
They had a pleasant surprise.
"I really focused on my defence," Dellavedova said.
"I know what the perception is about me defending quick guards."
Dellavedova proved perception only masquerades as reality.
"I thought I was really good defensively," he said.
It's worth mentioning that I wasn't particularly impressed with Dellavedova at summer league. He really struggled to initiate offense when pressured in the backcourt, and that hampered his ability to create for others. Having said that, if he can improve when facing full court pressure, his vision and shooting ability definitely have a place in the NBA.
Ultimately, he's at least someone to watch in the preseason as the Cavs look to fill out the roster. The Cavaliers' first preseason game is October 8th versus Milwaukee at the Q.