The Green Bay star -- who scored FOUR touchdowns in the Pack's 35-17 drubbing of Detroit -- told reporters after the game he believes he lost the necklace at some point during one of his endzone runs.
Green Bay Packers
Jones, though, was far from torn up over losing his dad's ashes ... in fact, he seemed to be at peace with it -- saying if he was going to lose it, he's sure glad it was in a touchdown scamper at Lambeau Field.
"If there was any place to lose it, that's where my dad would have wanted me to lose it," the 26-year-old running back said. "I know he's smiling."
Jones got the pendant -- a small black locket in the shape of a football -- sometime in the past few months ... following the tragic death of his dad, Alvin Jones Sr., who passed away in April at 57 years old from COVID-19 complications.