"Doris Roberts had an energy and a spirit that amazed me," Romano said in a statement to ET. "She never stopped. Whether working professionally or with her many charities, or just nurturing and mentoring a green young comic trying to make it as an actor, she did everything with such a grand love for life and people and I will miss her dearly."
The five-time Emmy-winning actress, who played Romano's lovably meddlesome mother, Marie Barone, on the long-running sitcom, died in Los Angeles on Sunday. She was 90.
Among the other Raymond stars paying their respects to Roberts are Brad Garrett, who played Roberts' other on-screen son, and Patricia Heaton, who played her daughter-in-law.
"I am deeply saddened by the passing of Doris Roberts, an amazing lady and brilliant actor," Garrett's statement read. "Doris was vibrant and full of life both on and off the stage, and I am so grateful we shared so many wonderful memories. I will miss her greatly and will always remember her incredible kindness, humor, talent and heart."
Heaton called Roberts' death "the end of an era" in a tweet.
Roberts is survived by her son, Michael Cannata, Jr., from her first marriage, and her three grandchildren.
Earlier this year, Romano said that a 20th anniversary celebration for Everybody Loves Raymond was already "in the works." The cast was expected to appear together at the ATX Television Festival in Austin, Texas, in June.
"I'm amazed. It seems to be just a common denominator that no matter where you're from, how you're brought up or your religion or beliefs, family is universal," Romano said, referring to the show's lasting appeal with audiences. "It resonates with people."