Ramos said he did not see the incident but stressed players had to accept it was a squad game.
"I think it is normal. Players want to play and they are disappointed when they are replaced," he said.
"It is football. We have got a squad and we have people on the bench and we have to share out the minutes between the people available."
Spurs No2 Gus Poyet also said Keane's reaction to being substituted showed that he was passionate about winning football matches for the club.
The Uruguayan added: "We will look at that, but it showed he wanted to be on the pitch trying to do what is right for the team. He is a good character and one we want to be on the pitch."