The move followed Ajayi winning Super Bowl LII Sunday against the New England Patriots.
Ajayi was traded to the Eagles on Halloween. Reports of verbal confrontations between Ajayi and Dolphins coaches surfaced before he was shipped to Philadelphia in exchange for a fourth-round pick in the 2018 NFL Draft. Gase criticized Ajayi for "trying to hit home runs all the time" on his runs.
The running back included an interesting caption on a photo of himself kissing the Vince Lombardi trophy on Monday.
"THEY may have tried to discredit you, discount you, throw dirt on your name...none of it matters now," Ajayi wrote on Instagram. "LEGACIES LAST FOREVER. Funny how they were GASsEd over journalistic...look at me now. ONLY GOD. YURP."
Ajayi had nine carries for 57 yards in Sunday's win at U.S. Bank Stadium in Minneapolis, Minn. The 24-year-old is under contract in 2018 but hits free agency in 2019.
Ajayi had 408 yards and a touchdown on 70 carries in seven games for the Eagles. He carried 138 times for 465 yards and didn't score a rushing touchdown this year for the Dolphins.
The former fifth-round draft pick didn't say much about Gase in the week leading up to the Super Bowl. Ajayi opted to take a sip out of his drink instead of answering when he was asked about his former coach during the Opening Night media scrum.
"I was going to work like a regular day [and] I got a phone call to come into work and obviously they told me right away when I walked into the office and yeah, that was that. I was a Philadelphia Eagle and my journey to being a Super Bowl champion began," Ajayi told reporters after the game.
"At the time there was a lot of emotions, but looking back at it, I'm so grateful for the opportunity of becoming an Eagle and now being a Super Bowl champion forever."