Palace's lengthy unbeaten away run in the Premier League - which had stretched back to October - was ended on Saturday by a Manchester City comeback either side of half-time.
Despite Palace racing into a two-goal lead, City got back level before half-time. Glasner made a tactical switch at half-time, sacrificing forward Mateta for an extra number in midfield, in the shape of Will Hughes.
However, City struck first within a few minutes, through Mateo Kovačić and would control the half. Two further goals ensured a final scoreline of 5-2 in the hosts' favour.
Palace will be given the chance of a quick response on Wednesday night, when making the trip to Champions League-chasing Newcastle United. And Glasner said Mateta had reacted well to the decision.
"I told him [Mateta] at half-time that it's a tactical decision," he said. "And I didn't really talk about it anymore because he knew it, he accepted it.
"We have quite a close relationship and of course I told him that he would start again tomorrow [against Newcastle].
"So there was nothing really to talk about. I know you take off your number one goalscorer at half-time and it's maybe big headlines for some, but for us it was not really an issue."
