A second-round pick (No. 39) by Dallas in the 2017 NHL Draft, Robertson has 125 points (58 goals, 67 assists) in 128 regular-season games and four points (one goal, three assists) in seven Stanley Cup Playoff games.
Goalie Jake Oettinger, who was a restricted free agent, signed a three-year, $12 million contract ($4 million average annual value) on Sept. 1.
"Anybody who knows [Jake] knows who he is as an individual, first of all," Nill said. "High, high-end character. First guy on the ice and last guy off. He works hard, he's committed to the game, and plays for his teammates. We're excited, we know what he can do."
The Stars (46-30-6) finished as the first wild card into the playoffs from the Western Conference last season and lost to the Calgary Flames in seven games in the first round.
"This is one of the more exciting camps I'm looking forward to," Nill said. "New coaching staff, it's a fresh start for a lot of players. And when I look at what we have coming into the organization, between the core that's been here for 5-10 years since I've been here, and we've had a new influx of talent -- the Jake Oettingers, the Roope Hintz, the Jacob Petersons coming in. All of a sudden we've got another flush of players coming in that are knocking on the door. We're excited with the depth, the new faces that are knocking on the door, and the opportunity that's available for everybody."
The Stars open the regular season against the Nashville Predators on Oct. 13.