MIAMI GARDENS, Fla. – Eugene “Mercury” Morris, who played for the undefeated Miami Dolphins of 1972 as part of a star-studded backfield and helped the team win two Super Bowl titles, has died, the team announced Sunday.

Morris, a three-time Pro Bowl participant, was 77 years old.

His family said in a statement that his “talent and passion have left an indelible mark on the sport.”

“Off the field, Mercury was a devoted father, a loving brother, a loyal friend and a pillar of the community,” his family wrote. “His presence extended far beyond football as he touched the lives of many during his time in Miami.”

We are deeply saddened by the passing of Dolphins great Mercury Morris. pic.twitter.com/V2t8SFNVvf

— Miami Dolphins (@MiamiDolphins) 22 September 2024

Morris was the starting halfback and one of three starting quarterbacks used by Dolphins coach Don Shula in Miami's back-to-back title seasons in 1972 and 1973, along with fellow Pro Football Hall of Fame inductees Larry Csonka and Jim Kiick. Morris led the Dolphins in rushing touchdowns in both seasons, finishing with an NFL-high 12 touchdowns and 10 more in 1973.

“This is a very sad day for me and our Dolphin family,” Csonka posted to X.

Those two seasons – the best in Dolphins history – also happened to be the best of Morris' eight-year career. In 1972, he rushed for a career-best 1,000 yards, and the following season he rushed for another 954 yards and a league-best 6.4 yards per carry.

Morris wasted no time making an impression with the Dolphins. In his first game as a rookie in 1969 against Cincinnati, he ran a kickoff 105 yards for a touchdown. That remains the most in team history, and his three kick return touchdowns and 26.5 yards per return average are also team records.

“I think Shula gave everybody that was coached by that guy a different direction and a different goal,” Morris said in 2008. “We were middle-class guys and middle-class fans, and Shula was a blue-collar guy. And he had a kind of work ethic that really showed you that if you work hard and do what you're supposed to do, things work out for you — not always, but you adapt to it and do what you need to do to try to do your best.”

Morris made no secret of his pride that the 1972 Dolphins were the first – and to date only – undefeated and tied team in NFL history to have a truly perfect season.

He also tried to make this clear: No, the Dolphins weren't beating the teams that came close to perfecting their feat, or having champagne chilled waiting for the moment when the last undefeated team of a season would be defeated.

“And just to be clear, we do NOT toast every time an undefeated team loses,” Morris posted on social media in 2015, when the Cam Newton-led Carolina Panthers started 14-0 before losing the second-to-last game of their regular season. “There's no champagne in my glass, just Canada Dry Ginger Ale! Ha!”

That sense of humor was sometimes directed at his beloved Dolphins. When Miami was 0-8 during the 2007 season, on its way to an 0-13 start and a 1-15 record, Morris cracked another of his many memorable jokes.

“The Dolphins don't embarrass me because our record is the best,” Morris said. “That's not my team. People say, 'Your team is playing bad.' I say, 'My team has all the AARP cards.'”

Born and raised in Pittsburgh, Morris played college football at West Texas A&M. In 1967, he was the nation's second-leading player in rushing yards behind OJ Simpson, and the following season he set national records: 340 yards in a game against Montana State, 1,571 yards in a season and 3,388 yards in a three-year career.

After his football career ended, he struggled with a number of personal problems, most notably his 1982 conviction for cocaine trafficking and sentence to 20 years in prison. He fought the sentence, admitting that he had used cocaine – in part to deal with numerous lingering injuries – but had never sold the drug. His conviction was overturned by the Florida Supreme Court in 1986, and Morris became a motivational speaker, urging people to avoid drugs.

“Was I bitter? Not really,” Morris wrote in his 1998 book, Against The Grain. “I wouldn't recommend going to jail for three days, let alone three years, to anyone. But I have to be honest: I had to go through what I went through to develop the character I had when I became a free man.”

Morris was inducted into the Dolphins Walk of Fame in 2013. With 3,877 yards, he remains fourth on the team's all-time rushing list, behind Csonka (6,737), Ricky Williams (6,436) and Ronnie Brown (4,815).

“Morris left a lasting impression with his dynamic play, personality and record-breaking performances,” the Dolphins wrote to X. “He loved the Dolphins, the fans and the South Florida community and will forever be remembered as one of the greatest players to ever wear the aquamarine and orange jerseys.”

The Associated Press contributed to this report.