Ink spot on Gretzky rookie card

Austin8

I am looking at a Wayne Gretzky O-Pee-Chee rookie card on Ebay. The seller confirms a small "ink" spot on the back of the card. He thinks it might be print defect, but it looks more like an ink spot to me. If it is ink, how will it affect the grade if I send it to be graded. Otherwise, the card is probably exmt-nm condition

doubledragon

If you don't get any answers over here, try the trading card section. There's a lot of OPC Gretzky experts over there.