The Dolphins confirmed Morrall's death Friday. Former teammate Charlie Babb said Morrall had been in failing health for some time.
When Bob Griese broke his ankle in 1972, Morrall came off the bench and started the final nine games of the regular season for the Dolphins. Morrall won praise from coach Don Shula for his willingness to step aside when Griese returned for the AFC Championship Game.
Griese started in the Super Bowl and helped Miami finish 17-0. That remains the only unbeaten season in NFL history.
Morrall also played for the Baltimore Colts, coming off the bench to replace an injured John Unitas and help the Colts to Super Bowl III, where they lost to the New York Jets. He was also the backup to Griese on the Dolphins team that won Super Bowl VII.
"I was very saddened to learn about Earl's passing," Shula said Friday in a statement released by the Dolphins. "All Earl ever did was win games for me, whether it was as a starter or coming off the bench. What I remember the most, of course, is what he did in 1972 when he replaced Bob Griese after Bob's injury and kept our perfect season going until Bob returned in the playoffs.
"But Earl won a lot of games for me in Baltimore as well. And he did it in such a humble way -- he was a great team player who would do whatever was asked of him. And he was an outstanding leader who inspired confidence in his teammates."
Morrall also played for the 49ers, Steelers, Lions and Giants.
The '72 Dolphins were led by such future Pro Football Hall of Famers as Shula, Griese, Larry Csonka and Paul Warfield, but their season might be long forgotten if not for Morrall, then regarded as a journeyman.
That's why Shula -- who also coached Unitas and Dan Marino -- held Morrall in special regard as a quarterback.
"When Bob went down, Earl stepped in like nothing happened, and we just won all the games," Shula said in a 2007 interview. "Then Griese was healthy for the AFC Championship Game against Pittsburgh, and I put Bob in the second half and he helped us come from behind and win the game.
"Then I had a decision to make, which to me has always been the toughest decision I've ever had to make -- who to start in the Super Bowl. Earl had done such a great job to get me there, but Bob was my quarterback going into the season, and he was my quarterback of the future. So I figured as long as Bob was healthy and ready to go, I was going back to Bob.
"So I've always said Unitas, Griese and Dan Marino are in the Hall of Fame, and Earl is in my own personal Hall of Fame."
Morrall said the 1972 Dolphins seldom dwelled on their perfect record as the season progressed because they were focused only on winning the Super Bowl after losing in the title game the previous year. He recalled a teammate raising the subject just once -- before the final regular-season game.
"We were going to play the Colts, and that's the only time I heard something about it in the locker room," Morrall said in 2007. "It wasn't about going undefeated. It was, 'Guys, if we're going to lose a game, this is the one to lose.'"
At 38, Morrall was the oldest player on the 1972 Dolphins. He attended their 40th reunion in 2012 and said he thought most of his ex-teammates looked good.
"We've all gotten a little bigger and stronger," Morrall said with a smile.
He was inducted into the Dolphins' Walk of Fame that year. Morrall also attended an 80th birthday party for Shula in 2010.
"We're just happy Don made it this long," Morrall said. "When he cut some of the players, they had ill feelings and might have got to him."
Morrall was a Michigan native who played at Michigan State. In retirement he lived in Naples, Fla., where Babb also lives.
"I was the youngest guy on the '72 team," said Babb, a defensive back. "Earl was 37 when I'm a 22-year-old rookie. He was kind of like Pops, and he was the king of the flattop. He was kind of a father figure to us young guys, until it was time to hit him. Then we didn't mind hitting him.
"Earl was a gentleman and a great representative of the NFL. He'll be missed."
Information from The Associated Press was included in this report.
Earl Morrall Dies
Earl Morrall, an NFL quarterback for 21 years who started nine games during the Miami Dolphins' perfect season in 1972, has died at the age of 79.