Matthew Morrison says Glee co-star Lea Michele has displayed incredible strength in the wake of Cory Monteith’s death.

The 26-year-old actress lost her longtime boyfriend and co-star to a heroin overdose July 13 and the entire cast has had a difficult time coping since returning to set.

Matthew, who plays Glee Club director Mr. Schuester on the show, says Lea has been a pillar of strength as they film a special episode in Cory’s honour.

“We’re in the middle of filming it, and it’s incredibly hard. We’ve mourned Cory, but now we’re mourning [his character] Finn. So it’s kind of like two people in that one person,” he told E! News.

“It’s incredibly hard and we’re staying strong together and I have to say Lea [Michele] has been the most strongest of all of us.”

Matthew, 34, admits the tragedy has brought the cast and crew closer together.

Lea, who plays female lead Rachel Berry, was part of the series’ original team of actors alongside Cory.

Matthew says the cast, which also includes Dianna Agron, Chris Colfer, Mark Salling, Jane Lynch, Darren Criss and Chord Overstreet, among others, has always been close but now the actors have all become “rocks” for each other.