Glasner said: "It was another great performance, but to be honest there were 10 to 15 minutes in the first half where we could have conceded especially from set-plays.
"But after the second goal and some small adaptations at half-time, we could see how the players are enjoying playing together and and having fun on the pitch, so it was a great end to the season."
On Mateta, he said: "He has a lot of confidence. He makes the runs, he works hard and he has a great finish but he needs the support of all his team-mates."
Asked if they can keep Mateta, Eze and Michael Olise, he added "The club is working hard that we can keep all the players and what we could do is show that we are ambitious, the journey and the direction that they can go in, that they can express themselves and show all their qualities.
"Crystal Palace, with these fans and this team is a good place to stay."