Mateta, 28, is Palace’s high scorer this season with eight Premier League targets however informed the membership he needed to go away earlier in January.
“Once more, there may be a lot noise, a lot hypothesis, so many issues occurring,” added Glasner.
“We want each single participant at their greatest and JP [Mateta] is not at his greatest proper now with all of the noise that occurs.
“It may be soccer noise, but when somebody has personal points the place they can not deal with soccer, then it is not sensible to play.
“He can not help the staff and carry out at his high degree. We determined it’s higher to not play him.”
Palace sit fifteenth within the Premier League and have already bought captain Marc Guehi to Manchester Metropolis throughout the winter window.
They’re but to discover a alternative for the England worldwide however Glasner, who stated earlier this month that he might be leaving on the finish of the season, is assured the membership are working to bolster the squad earlier than Monday’s deadline.
Palace have boosted their ahead choices by signing Evann Guessand from Aston Villa on mortgage with an choice to make the transfer everlasting.
“The membership is working nearly 24 hours a day proper now,” Glasner stated.
“Marc [Guehi] left two weeks in the past and no one is in. You’ll be able to think about it isn’t really easy – each staff desires to play a profitable season, so it isn’t really easy that you would be able to get the gamers on the finish of January.
“I see the membership working onerous to get gamers in to switch Marc and, in fact, we now have to arrange if one thing occurs with JP [Mateta].”
Glasner stated the membership is getting ready for various eventualities and Wolves striker Jorgen Strand Larsen stays a goal.
“To be clear, it may be that Mateta stays, and he’s a Palace participant on 2 February, and it may be that Mateta has left the membership and a brand new striker is in,” stated Glasner.
“These are the 2 conditions we’re speaking about and discussing proper now.”
Palace have been additionally prepared to supply £50m for Norway striker Jorgen Strand Larsen, however that deal is now within the steadiness after the Eagles communicated their intention to stroll away.
Wolves boss Rob Edwards confirmed on Friday that 25-year-old Larsen is able to play towards Bournemouth on Saturday.
