As the NHL has been going through something of a transformation [VIDEO], one of its stars is calling it quits. Swedish-born center Henrik Zetterberg has opted to end his playing career. His ongoing struggles with a degenerative back injury is the apparent reason.

Zetterberg has one of hockey's most distinguished careers

After five seasons in Sweden's top hockey league, Zetterberg debuted with the Detroit Red Wings in 2002. He had previously been drafted by the team in 1999. Additionally, he had served in the Swedish Army in his late teens. Zetterberg ultimately played 15 seasons with the Red Wings. Along the way, he played another season in Sweden and one in Switzerland during NHL strikes.

In 2013, he took over the captaincy of the Red Wings.

His career highlights include being named to two NHL All-Star teams. Zetterberg also helped the Red Wings win the 2008 Stanley Cup Championship. That year, he was awarded the Conn Smythe Trophy as the Most Valuable Player of the playoffs. Previously, he had been a two-time All-Star and the equivalent of MVP in 2002 in Sweden.

Internationally, Zetterberg helped Sweden win a world championship in 2006. It followed a silver in 2002 and bronzes in 2001 and 2002. Also in 2006, Zetterberg and Team Sweden won the Olympic Gold Medal [VIDEO]. He was later a member of the 2014 Olympic Silver Medal team. However, his back led to his playing time being severely limited. TSN reports that Zetterberg is one of 28 members of the 'Triple Gold Club.' This refers to players that have won a world championship, Olympic Gold Medal, and Stanley Cup Championship.

In 2014, Zetterberg underwent surgery on his back. To continue his playing career, he would likely need another one. He has instead opted to move on, rather than suffer serious injury. His immediate future is unclear, but Zetterberg does have a wife and young child to focus on.

Although Zetterberg won't play, he would still technically be under contract for three years. He would not be officially retired until the end of his contract.

His retirement is part of the end of an era for the Detroit Red Wings

Recently, the Red Wings had one of the greatest stretches of time in sports history. They made the playoffs in 25 consecutive seasons, winning the Stanely Cup four times along the way. More recently, the Red Wings had to begin a rebuild for the future. The team has also missed the playoffs twice in a row.

With Zetterberg's departure, there are only a few remaining members from the team's glory days. It's likely not long before the turnover of players is complete, as the Detroit Free Press indicates.