Hockey legend Gordie Howe, best-known for his hard-nosed, high-scoring game on the ice and his gentlemanly conduct off it, has died at the age of 88.

The man they called "Mr. Hockey" passed away Friday morning with his family at his side, according to a statement issued by the family through the Detroit Red Wings organization.

Howe had been struggling with health issues since suffering a stroke in 2014, which left him unable to walk and barely able to speak. The Howe family said his health improved in 2015, after he received an injection of stem cells at a Mexican clinic.

Howe earned the nickname "Mr. Hockey" for his lengthy career that included 25 years as a Detroit Red Wing, four Stanley Cup championships, six Hart Trophies as the league's most valuable player, and numerous records.

Known for his prolific goal-scoring ability and his physical play, Howe played his first NHL game on Oct. 16, 1946 at the age of 18, and scored a goal in his debut. He retired in 1971 and was inducted into the Hockey Hall of Fame a year later. However, after rejecting a coaching post with the expansion New York Islanders, Howe eventually made a comeback with the upstart World Hockey Association, where he joined his sons, Marty and Mark, with the Houston Aeros.

Howe played for the Aeros and the New England Whalers of the WHA from 1973-1979, then returned to the NHL when the league absorbed the WHA in '79.

At age 51, he played his last full NHL season with the renamed Hartford Whalers in 1979-80. Howe turned 52 before the season ended, and earned himself the record for oldest player to have played in the NHL, beating runner-up Chris Chelios by four years.

Wayne Gretzky, who grew up idolizing Howe and chose his No. 99 as a tribute to Howe's No. 9, expressed his deep sadness on Friday. "Unfortunately we lost the greatest hockey player ever today, but more importantly the nicest man I have ever met," Gretzky said on Twitter.

Gretzky often referred to Howe as his hero. In the NHL, they crossed paths in 1980, when they both played in the All-Star game. They later built a friendship that lasted for many years.

Gretzky went on to shatter many of Howe's records, but "Mr. Hockey" still holds a prominent place in the hockey record books.

Howe's records include:

Most NHL regular-season games played (1,767);

Most regular-season points by a right-winger (1,850);

Most consecutive 20-plus goal seasons (22);

Most All-Star Game appearances (23).

NHL Commissioner Gary Bettman called Howe a "beloved ambassador" of the sport, in a statement issued following his death. "Gordie's commitment to winning was matched only by his commitment to his teammates, his friends, to the Red Wings, to the city of Detroit and – above all – his family," Bettman said.

"He embodied on and off the ice what it meant to be both a Red Wing and a Detroiter," Red Wings owner Mike Ilitich said in a release. "He was tough, skilled, and consistently earned success at the highest level. His achievements are numerous and his accomplishments immeasurable."

Red Wings GM Ken Holland also praised Howe for his role as an ambassador in the city where he played 25 seasons in his career. "He was as fierce and competitive as they come but away from the rink he was truly engaging and personable," Holland said in the Red Wings statement.

Prime Minister Justin Trudeau offered his condolences to the Howe family in a statement too.

"Gordie was an incredible athlete who relentlessly pushed the limits of the game," Trudeau said in the statement. "We will remember the legend, the man, and the many exciting hockey moments he provided to fans throughout his career.

"Skate on, Mr. Hockey. You will be deeply missed."

Howe is survived by his three sons and a daughter. His wife, Colleen, died in 2009, and his younger brother Vic passed away in 2015.