While filling in for Hoda Kotb on "Today with Hoda and Jenna" Wednesday, Lynch, 60, remembered Rivera as a "force of nature."
"It's just gut wrenching and heartbreaking that she is gone … with Naya you felt like somebody had your back," she said. “I think that one of the things that kind of got lost when we were doing the show is what a force she was because there were so many talented people … she blew everybody away.”
Gloria Estefan, who played Rivera's mother on "Glee" and served as a music producer for her later, shared a similar sentiment.
In a radio interview with Andy Cohen on Wednesday, she said starring alongside Rivera was a "joy," recalling her having "really amazing (singing) chops" and being "really down to earth and warm."
"I hope she's remembered as a wonderful triple threat," Estefan said. "She really was one of our young acting talents and dancing and singing. It's just such a shame. It broke my heart when I saw that picture of her mother on her knees by that lake. I can only imagine what that felt like."
Estefan added that when she heard the news about Rivera and her son, Josey, who was found safe on board the boat Rivera had rented, she was "praying beyond words that maybe she'd been caught up in a riptide and somehow ended up landing in some other part around that lake.
"Deep down inside as a mom, you know that she would never have left that baby alone on the boat so something terrible must have happened," she said.
Remembering Naya Rivera: 'Landslide,' 'Smooth Criminal' and more of her best 'Glee' moments
Earlier this week, Heather Morris had a message for "Glee" fans mourning Rivera: "You're not alone."
Morris, 33, wrote those words in an Instagram post Sunday that featured a tearful discussion mourning Rivera and celebrating the duo's historic onscreen relationship.
"I want you to know that we are all here with you, that grief looks different on everybody and I want you to be gentle and kind to yourself during this time," Morris said to fans in the video. "I think a lot of you may feel very far away and I hope this message will help you feel closer."
"I have been feeling very heavy lately. I’ve been feeling this aching in my heart to connect with my fans, to connect with everybody who’s been feeling a little lost and a little confused during this time," she said.
In a tragic series of events last month, Rivera disappeared from a boat she rented with her 4-year-old son, Josey, at Ventura County's Lake Piru on July 8. After a days-long search, the Ventura County Sheriff's Office announced on July 13 that a body found at the lake was Rivera.
In the Instagram video, Morris reflected on her "Glee" character Brittany Pierce’s relationship with Rivera's Santana Lopez, a groundbreaking example of LGBTQ representation in television for the Fox show.
Morris said there was little reason to explain the importance of the screen relationship "because most of you felt like it was your gateway into your current life. Most of you felt like it was an inspiration to become your best self."
Morris continued: "I want you to know that that was never lost on me. It was never lost on Naya. We both knew how special that was. I think she knew a little bit more than I did. I really felt it a lot later with all the messages and all the people reaching out. and I knew the writers also knew that as well. They were basically writing for the fans."
The "Glee" star tried to fight back tears as she explained, "I know a lot of you feel very lost and very far away from what happened, maybe a bit confused. And that’s completely normal. But I felt like it owed it to you guys."
"I want to thank you all for being such advocates and so supportive of Santana and Brittany’s relationship," said Morris. "Because without you guys it never would have existed. You guys helped create something for the writers and, for Naya and I, that made an impact that will last for a lifetime and beyond that."
Rivera herself told The Hollywood Reporter in 2012 about the TV relationship, "I get so many stories of people that the storyline truly touched them and and hit home for them. It's created a fan base for me that I never thought I'd have ... It's really cool to know that there are people out there that this does matter to and that your work does matter."
This article originally appeared on USA TODAY: Naya Rivera: Jane Lynch, Heather Morris mourn death of 'Glee' co-star