Saquon Barkley is jumping in to save the day for a dissed Giants fan ... he just invited the little kid who was roasted by DeMarcus Lawrence to a game in November!!!
11-year-old Kamil Bautista -- a NY fan living in McAllen, Texas -- drove 9 hours with his family to watch the Cowboys play the Giants in Dallas last weekend.
But, after the game when he was searching for autographs from players outside the stadium ... Lawrence blew him off, telling him his Barkley jersey was the wrong team!