Mateta was taken to hospital during Palace's FA Cup win against Millwall. The striker was on the wong end of a collision with Millwall goalkeeper Liam Roberts, who sent off for his action.
Palace stated on Saturday evening:
"We are very pleased to confirm that JP Mateta has this evening been discharged from St George’s Hospital where he received specialist treatment and 25 stitches to a severe laceration to his left ear. All scans were clear and JP is feeling well.
"He will now rest and recuperate over the following days where his progress will be monitored by our club doctor.
"Thank you to the medical staff at both Selhurst Park and the hospital for their help and professionalism, and for all the wishes of support that JP and the club have received today."