Mateta has been absent since his Deadline Day move to AC Milan fell through after a persistent knee injury caused him to fail his medical.
The 28-year-old will return to training next week and may be ready to play a minor part in the first leg of their Conference League Round of 16 tie against AEK Larnaca next Thursday.
Despite missing Palace’s last seven games while recovering from a knee injury sustained on international duty with France in November, Palace boss Oliver Glasner would not rule out an operation in the long-term.
“We’re planning for Mateta to be partly integrated next Monday in the team’s training for the Larnaca game next Thursday. He won’t start, but can maybe play for 15-20 minutes.
“He was out for a long time, but his knee looks better now. That’s why we have decided to now reintegrate him step by step.
“He hasn’t been on the pitch for five or six weeks now. We have to be careful, but the goal is that he is available for the Larnaca and Leeds games.
“Everybody tries to solve a physical problem without surgery, which is always the main goal.
“The common opinion is that the best way is to try it the conservative way, without surgery.
“Depending on the reaction of the knee, surgery could be neccessary but it’s not guaranteed. Everyone hopes JP doesn’t need it.”
With less than 18 months remaining on his Palace contract, surgery could complicate the Eagles’ hopes of selling Mateta in the summer.