However, the actor told The Washington Post that he has "no idea" which stars will exit the Fox musical.
"I mean, the show's back next season, but we don't even know which cast members will actually be back," he explained.
"I think I'll be back, but some of the kids... we're trying to figure out what we're going to do with that."
Morrison - who plays Will Schuester - added that the departures will be handled "very sensitively".
"For a lot of these kids, it will be their last show," he said. "I'm really happy that they're treating it with such sensitivity and making the stories so great to end the show for some of these people."
The 33-year-old star also commented on the rumours that Lindsay Lohan had angered the Glee cast by arriving late when she filmed a recent guest spot.
"I saw her on set, but I never worked with her," Morrison claimed. "I think it was all right. The work got done."
Glee airs on Tuesdays at 8/7c on Fox, with the season finale scheduled for May 22. The show airs on Sky1 in the UK.
> Chris Colfer: 'I don't want to say goodbye to Glee'