Clooney, 52, said the scene was there from the very beginning and he merely suggested something as director Alfonso Cuaron and the team was struggling with it, reported E! online.
"I didn't write any scene. That scene was there from the minute I was handed the script. The problem they were having was afterward," he said.
The scene is the one in which Sandra Bullock's astronaut dreams that she is having a conversation about her daughter with Clooney's character as she prepares to head back to earth.