David Mulugheta, who is an agent with AthletesFirst, took to Twitter and posted a photo of the ring, saying he and his wife were driving around in the car when they spotted the ring.
Mulugheta tweeted he would send the ring back to Seahawks safety Earl Thomas to have it returned to Coleman.
Coleman is in his second season with the team. He played in five games this season, catching two passes for 29 yards and a touchdown.
The Seahawks take on the Carolina Panthers in the NFC Divisional Playoff on Saturday.
GALLERY: A LOOK AT EVERY SUPER BOWL RING
- Scooby Axson