Several Thunder players posted photos on their social media showing the nose of their plane smashed in after landing shortly after 1 a.m.
Carmelo Anthony posted a photo with the caption, "What possibly could we have hit in the SKY at this time of night? Everyone is Safe, Though."
Delta Airlines spokeswoman Elizabeth Wolf said maintenance was evaluating the situation and that the damage was likely caused by a collision with a bird. She said the Boeing 757-200 landed safely without incident.
A team official told ESPN that the flight was a little rough but not extreme or out of the ordinary.
The Thunder were traveling from a game in Minnesota. They play the Chicago Bulls Saturday night at the United Center.
The Associated Press contributed to this report