"It's significant," Lillard said of his role, per Casey Holdahl of the Blazers official site. "It's not a cameo."
LeBron James will star in the movie—set to be released in 2021—taking over the Michael Jordan role from the original 1996 version.
Lillard will be part of the supporting cast, which also includes NBA All-Stars Anthony Davis and Klay Thompson, as well as WNBA star Diana Taurasi.
While the first Space Jam movie featured contemporary big names like Charles Barkley and Patrick Ewing, it seems like the current crop of players could be even more involved in the next film.
As Lillard explained, filming included "15-hour days, showing up on the set at 6 a.m., leaving at 9 p.m. It was long."
"I'm not going to say it was fun," he added, "eventually it was fun, and now I'm happy I did it knowing that I was a part of something like that. I think it's going to be great."
The 29-year-old has seen his profile rise significantly in recent years despite playing in a small market. Lillard earned his fourth All-Star selection this past season before carrying the Trail Blazers to the Western Conference Finals.
He signed a four-year, $196 million supermax contract extension this summer.
Adding a major role in a highly anticipated film could help make him one of the most recognizable players in the NBA.