With so many moves in the NBA this offseason, either via free agency or trades, the issue of loyalty on both sides has become a hot topic.Last summer, Kevin Durant was lambasted for his decision to leave the Oklahoma City Thunder to join the Golden State Warriors after nine years with the organisation and became a villain to the fans who adored him.But after the Boston Celtics surprisingly traded point guard Isaiah Thomas despite his hugely successful stint with the organisation, many players across the league took exception and blasted fans for not taking the same angry approach towards teams when they offload players.But one man who has never had this problem and is the epitome of loyalty is Dallas Mavericks star, Dirk Nowitzki.The German has spent his entire 19-year NBA career with the Mavs and has never contemplated leaving for another team.He has developed a special bond with the city of Dallas, its fans and owner Mark Cuban which has seen him remain loyal.Over the years, the 39-year-old has even taken a reduced salary in order to help the team improve its roster and chances of winning.This is something that the Mavericks faithful are grateful for and one fan recently decided to go the extra mile to show his appreciation for the big man.Dirk took to Twitter to post a picture of a card sent to him by a fan which included a $20 note and the following message:"You been taking discounts the past 6 years to help the team bring talent and a title … LUNCH IS ON ME BIG FELLA!"

The 13-time All-Star is entering his 20th campaign with the Mavs and the two parties mutually agreed not to exercise his $25 million option for this season, with him instead signing a two-year, $10m deal.

He also took a significant pay cut in 2014, electing to stay on a three-year, $25m contract instead of signing a max contract elsewhere.

Nowitzki delivered the franchise's only championship in 2011 and has been leaving money on the table ever since in an effort to help them compete with the best teams in the league.

According to Business Insider, the All-NBA power forward has foregone almost $194m to remain in Texas.

His financial sacrifices haven't led to success on the court for Dallas, however, as they've failed to make it out of the first round of the playoffs since winning the title in 2011 and missed out on the postseason altogether.

But he is a true Mavericks legend and will be a Hall of Famer when he eventually calls it a day.

For now, though, he's not ready for retirement just yet and is preparing for a new season which begins at home to the Atlanta Hawks on October 18.