Palace manager Oliver Glasner declared on Friday that Mateta is clear to feature against the Cottagers later on Saturday.
It will be the French striker's first appearance since his ugly collision with Millwall goalkeeper Liam Roberts three weeks ago left Mateta needing 25 stitches in a head wound.
Mateta is now back and will wear a 'water polo' helmet similar to what former Arsenal and Chelsea goalkeeper Petr Cech wore in the final years of his career.
Mateta played an hour in a friendly during the week as he tested several forms of headgear before settling on the water polo version. The FA have also approved the helmet.
Glasner said: “It’s like a water polo helmet. But with one ear. In water polo it’s so they don’t get water into their ears, he has it just on one side. It sounds crazy but we are used to it.
“I said to the doctor I remember Petr Cech wearing this helmet and he said: ‘Yeah but the ear was free so we need the full helmet’. Once he wore one like you use to ride a motorbike but he couldn’t train with this because it was too heavy, then we found the right one.
“He has trained with us for two weeks with this protection. It’s also important for him to train a little bit with an internal game in the international break so he could play for 60 minutes without any problems so he’s ready."