Former Miami Dolphins running back Jim Kiick has died, the team announced Saturday. He was 73.

Kiick had been living in an assisted living home for the past few years. His daughter, Allie Kiick, a professional tennis player, said he had Alzheimer's disease.

Kiick was a vital member of the 1972 Dolphins team that went 17-0 and won Super Bowl VII and the group that repeated as champions the following year by winning Super Bowl VIII.

Our thoughts and prayers are with the family and friends of Jim Kiick. pic.twitter.com/ufih9qRDMt

— Miami Dolphins () June 20, 2020

Known for his versatility as a runner and a receiver, Kiick was part of a three-headed backfield with Pro Football Hall of Fame fullback Larry Csonka and Mercury Morris during the peak of the Dolphins' dynasty in the late 1960s and 1970s. He played seven seasons in Miami.

Along with Csonka, his best friend, they earned the nicknames Butch and Sundance, inspired by the popular 1969 movie "Butch Cassidy and the Sundance Kid.''

Kiick ("Butch") made the American Football League All-Star team in his first two seasons. He had two touchdowns for the '72 Dolphins in the AFC Championship Game, and also scored in the Super Bowl victory that capped the team's 17-0 season under Pro Football Hall of Fame coach Don Shula, who died May 4 at age 90.

Kiick and the speedier Morris split playing time during the 1972 and '73 seasons, which gave Shula a potent one-two punch at halfback but sometimes led to second-guessing by fans.

"Kiick and Mercury Morris both contributed,'' Shula said. "Every Monday there was a controversy, but the bottom line wasn't bad.''

Csonka compounded the challenge for opponents. He and Kiick met at an all-star game the summer they joined the Dolphins, and as running mates they roomed together, partied together and briefly held out together seeking better contracts.

In 1975, Kiick, Csonka and future Hall of Famer Paul Warfield left the Dolphins for the WFL. The package was a watershed worth nearly $4 million over three years for the three players, who played for the Memphis Southmen.

But the WFL folded, and Kiick returned to the NFL for his final two seasons, playing for Denver and Washington.

James Forrest Kiick was born Aug. 9, 1946 in Lincoln Park, New Jersey. He led Wyoming in rushing three years in a row and was inducted into their athletics Hall of Fame in 1996.

Miami drafted Kiick in the fifth round in 1968. He became a starter as a rookie and led the AFL in rushing touchdowns in 1969 with nine.

He had his best season statistically for Miami's 1971 Super Bowl team, when he rushed for 738 yards and averaged 4.6 yards per carry, both career highs.

Kiick also was an excellent blocker and a threat as a receiver. He had 233 career receptions for 2,302 yards.

Following retirement, Kiick worked as a private investigator for the Broward County public defender's office. His father, George, played fullback for the Pittsburgh Steelers in 1940 and 1945.

"He is the best dad I could have ever asked for, and will forever be a legend and my hero,'' Allie Kiick, who has been ranked in the top 150 on the women's tour, wrote on Twitter after his death.

Because of the coronavirus, she wrote on Thursday that visitors weren't being allowed in her father's room at the assisted living facility.

"I miss my dad,'' Allie Kiick tweeted. "It's pretty hard when you're sitting on the outside of the glass and can't do anything to cheer him up. He's lost the spark in his eyes as anyone would in this situation.''

Information from The Associated Press was used in this report.