Jones said Marlo, the youngest of his five children, died on Friday.
"We know that everything that We do from here on out will be with you. Every step we take, you will be with us," Jones said on his Instagram page. Whenever we have a bad day, We will think of your smile. We miss you already buddy and will forever love you. Rest peacefully our sweet baby boy. You have gained your wings."
In a statement, the Lions commended Jones and his wife as Jazmyn as being pillars of the community, and asking for privacy for the family in this most difficult time.
"The Detroit Lions fully support Marvin and Jazmyn during this extremely difficult time," the statement said. "Marvin and Jazmyn embody the true meaning of family, and the example they set has made them an inspiration to so many in our community. We thank everyone for the outpouring of support."