Pro Football Talk reported earlier in the day that the Dolphins wouldn't match the offer. The deal comes with $20 million in guarantees.
The Dolphins placed the transition tag on Clay, making him a restricted free agent and Miami had five days to match Buffalo’s offer.
Clay, 26, will reportedly receive $24.5 million in first two years of the deal.
Clay had 58 receptions for 605 yards and three touchdowns last season.
Buffalo’s offense ranked 26th in the NFL in 2014, with the four tight ends on their roster catching 69 passes for 715 yards.
- Scooby Axson