Salling, who is returning full-time to the Fox show for its final season
, admits there will definitely be something missing in the show finale.
"Cory Monteith was a great leader as a character and person in real life," he tells People
. "It's a big, obvious hole. I still think about him all the time."
"He was kind of like the quarterback of the show, which sounds cliché because the [tribute] episode was called that, but he was kind of like that in real life," he added.
Though Salling says it's like reuniting with "family" coming back together with the cast members of the show for the final season, he admits that it still doesn't bring any closure when it comes to Monteith's passing.
"I don't think there will be any closure. Not yet," he says candidly.
In October, show creator Ryan Murphy dished to ETonline
about the sixth and final season of Glee
, which features Rachel Berry (Lea Michele) coming home to Lima after her humiliating failure as a TV actress. She then discovers that Sue Sylvester (Jane Lynch) has banished the arts at McKinley.
"We've really listened to what the fans want," he said. "Everything that I've been reading from the last four years about what the fans want from Glee is what they're going to get."
He also revealed some cryptic details about Glee's very last scene, which was originally supposed to be a heart-warming moment between Michele's Rachel Berry and Monteith's Finn Hudson.
"It used to end with Cory and Lea and it was a much more micro relationship ending," he said. "But I think we've taken the heart of what we were going to do and expanded it so it feels more macro and universal and I'm happy with that."
Glee's final, 13-episode season starts with a special two-hour premiere event on Jan. 9, 8 p.m. on Fox.