Reilly, 25, originally signed on with the Bills as an undrafted free agent out of Nebraska back in 2017. He spent over a year in Buffalo before he was waived coming out of the preseason last year.
The Lions later signed Reilly to their practice squad and he would later catch on with the Cowboys. Detroit brought Reilly back on a futures contract this past January before waiving him again in May.
Reilly returned to the Lions in June.
During his four-year college career at Nebraska, Reilly caught 70 passes for 1,275 yards receiving and six touchdowns over the course of four seasons and 28 games.