But those who knew Johnson and those that had seen him play raved about him. They knew at the time what everybody knows now: This kid can play.
Indiana ripped Johnson away from ACC country, beating out both North Carolina and Virginia to land the four-star guard. With each passing game, it becomes more and more evident just how big that recruiting win was for Tom Crean and Co.
Through 10 games, Johnson is averaging 10.1 points, 4.1 rebounds, 3.5 assists and 1.1 steals in 27.9 minutes per game. He's shooting 50.7 percent from the field and 40 percent from beyond the arc.
As is often the case, though, Johnson's importance to the Hoosiers cannot be measured by the box score alone. He came in as the strongest freshman Crean had ever seen, and he's now bench-pressing the second most on the team. That's a remarkable feat.
"Rob Johnson is a guy getting a lot done for us," Crean said recently. "It's not just showing up in the numbers but we're asking a lot of him. We're asking a lot of James and Rob. And for them to play 10 games and play at the level that they're playing at says a lot. It really does."
Johnson has also quickly become one of Indiana's best on-ball defenders, due in no small part to the fact that he fears no one on the court. Johnson's warrior-like demeanor is unique for a freshman, and that's why he's hardly looked like one in his first 10 collegiate games. He's ready and willing to accept any challenge Crean and his staff throw at Johnson.
Case in point: When the team is doing drills in practice, Johnson demands to guard junior point guard Yogi Ferrell. He wants to go against the best.
"I try to match up with him so I get the most out of what we're doing," Johnson said. "I've already gotten better from practicing against him. I'm just going to keep getting better. One thing coach Crean always says is, 'If you can keep his dribble under control, you can keep a lot of other guards around the country under control.'"
Johnson likes going head-to-head with Ferrell to help him grow as an on-ball defender, but also to learn to be a more pure point guard. Johnson was recruited as a combo guard that could play both positions, but he'll likely have to play the point if he hopes to be drafted in the NBA. Johnson is also the Hoosiers' back-up point guard, a role he's mostly excelled in, with the exception of a game against No. 4 Louisville. Ferrell proved to be IU's only reliable ball handler against Louisville's relentless full-court pressure.
What that tells us: Johnson isn't there quite yet. But he's working to get there.
"I think the biggest thing I've been working on is just my decision-making as a point guard, trying to play at a fast pace but still under control and making the right decisions," Johnson said.
Johnson might not always put together headline-grabbing scoring performances, but he's a player that you're likely to fall in love with, if you haven't already. At his core, Johnson is a tireless worker that won't back away from anyone. He's the type of player that helps teams win championships, a guy you'll feel proud to cheer for.
"Rob is adjusting great. He's adjusting a lot better than I did last year," sophomore Collin Hartman said. "He's very strong, extremely strong in the weight room. He can push the ball out, guards multiple positions, very quick, shoots the lights out."
The Indiana program was in good hands with the likes of Jordan Hulls, Victor Oladipo, Will Sheehey and others that transformed the basketball culture in Bloomington. With guys like Johnson and Blackmon in the program now, it's safe to say it remains in good hands.
"As a high school player and pretty much all my life, I've been a gym rat," Johnson said. "I think it's good to come in here with a group of guys that like to work outside of practice just as much as me. It keeps you that much more focused and hungry.
"I feel like I'll be ready to accept any of the challenges. Whether that's guarding the best player or shooter or whatever it might be, I think that's something I'd be ready to do."