The Eagles manager confirmed the news in the embargoed section of his pre-match press conference, with Mateta returning to the starting XI after featuring from the bench in Palace's last two Premier League matches against Liverpool and Nottingham Forest.
Glasner said of Mateta: “I can tell you he will start against Tottenham.
“[Last season] was his highest scoring [season] for Crystal Palace ever [with 19 goals in all competitions] – and then expecting now it's time for the next record, it's time for the next record… it's not too easy.
“I read an interview from Phil Foden. He said so many games had passed, and then the Euros… He's not in the shape that he has been last year. Many games. And maybe it's the same with players.
“We have players who are not used to having this programme that they had: end of season, going to a tournament, playing for their country, up to the finals, so I think for everyone it was the first time. And then you have to deal with it, and this is a process. And it's also one small reason maybe that we don't have the results that we all would like to have.”