In November of 2009, Novak Djokovic signed a 10-year apparel deal with Sergio Tacchini, as his former sponsor adidas put its money in Andy Murray. It was a huge coup for the brand, who once had Pete Sampras and John McEnroe, but hadn’t been able to find relevance.

But on Tuesday, Tacchini announced in a statement that the two had mutually decided to part ways. The reasoning? The small brand couldn’t handle the success that the Serbian player had with them.

In their clothes, Djokovic has won four majors, including the Australian Open twice. He has also won 84.7 percent of his matches (161 out of 190) and has been No. 1 in the world for nearly 11 consecutive months.

The story of how the deal unraveled is hard to fathom.

Sources tell CNBC that Tacchini was able to sign Djokovic by offering him a smaller guarantee than the larger companies would pay, but promised bigger should he do well. When Djokovic kept winning, the company fell behind on payments to the tennis star.

A few years ago, I attended a military recruitment session with NASCAR driver Ryan Newman, who is sponsored by the U.S. Army. Many had criticized the sponsorship as a waste of money, but Newman and an Army official told me that day that the numbers actually made sense.

I took their word for it.

Fast forward to this week. On Thursday, an amendment attached to the $608 billion defense bill that prohibits every sports sponsorship from the U.S. military, was passed by the House Appropriations Committee.

The hottest NFL rookie endorser, Robert Griffin III, has scored yet another sponsorship deal.

On Thursday, athletic protective gear company Evoshield told CNBC it had signed the No. 2 overall draft pick, who had carved the niche market out of his adidas deal so that he could sign with the brand.

Justin Niefer, Evoshield’s director of product development, said that RGIII was wearing Evoshield since his freshman at Baylor, thanks to a relationship the company had made with the football team’s equipment managers and trainers.

With more people than ever before paying attention to preventative protection on the field, companies in the sports protective gear space have seen sales skyrocket. Niefer says that Evoshield’s revenues have doubled every nine months for the last couple years.

“In the past, no one wanted to wear protective gear until after they got hurt,” Niefer said. “But that has changed. “Schools, teams and now players themselves are finally realizing that their body is their biggest investment. Guys like RGIII have worn our stuff not after he got hurt, but to protect himself from getting hurt.”

The company liked the speedy RGIII to be its first football endorser to help them shed the stigma that protective gear has to be bulky.

In October, a week after its chancellor agreed to explore leaving the Big 12, the University of Missouri produced a 45-page document, outlining the pros and cons of going to the Southeastern Conference (SEC).

In the report, which the Associated Press said it had obtained, Missouri said it could earn as much as $12 million more per year from an new TV deal in the SEC compared to the deal it had in the Big 12.

The Big 12 asked to see the report, and asked Missouri to show them who did the study and how they came up with the number. Missouri wouldn’t.

As the Oklahoma City Thunder gets ready to take on the Los Angeles Lakers in the Western Conference semifinals tonight, there’s an off-the-court distraction that could impact the team’s business.

Chesapeake Energy CEO Aubrey McClendon, who owns 19.2 percent of the Thunder, has been under fire in recent weeks for admitting to his participation in a program that enabled him to buy a personal stake in every well the company drilled.

This, along with pushing the company’s debt up to a reported $15.6 billion and running a hedge fund on the side, resulted in the company agreeing to terminate the program and forcing McClendon to relinquish his chairman title.

So why does this have any impact on Kevin Durant, Russell Westbrook and James Harden?

Ten days after the FDA sent warning letters to manufacturers of supplements with DMAA in it, the nation’s largest supplement retailers still have the product on the shelves.

Both GNC and Vitamin Shoppe continued to sell the popular pre-workout like OxyElite Pro and Jack3d in its online and physical stores as of Tuesday morning.

Vitamin Shoppe CEO Tony Truesdale told analysts on a conference call that he didn’t see the category as an area that could have a material impact on the company’s business. Truesdale pointed out that the company has 8,000 different product offerings and believes it’s diversified to make it through a possible government shutdown of the ingredient.

I’ll Have Another wasn’t exactly a huge longshot, but he certainly was getting treated like one. But there was the horse, in Friday’s New York Times, predicted to come in dead last.

“Santa Anita winner has overachieved,” wrote the well-respected Times horse racing reporter Joe Drape,” but there won’t be any magic here.”

Drape was one of the few who boldly predicted how the entire field would finish and decided to put 12 horses with longer odds ahead of I’ll Have Another, who of course went on to win the Derby.

“I did hear about that particular prediction,” said J. Paul Reddam, the horse’s owner. “At first when you read what the pundits say it can kind of be a little bit unnerving because it will be different from your own opinion and you wonder how much bias you have. But if you go and you look, you’ll see that that particular writer had him last, but somebody else had him first.”

That actually would be quite hard to find.

At the 2010 Keeneland Yearling Sale, bargain hunter Bob Zollars had his eye #1475.

Unable to spend big for a horse by a top sire, Zollars followed the family history of the horse’s mother, Follow Your Bliss, whose was fathered by Thunder Gulch, best known for his win in the 1995 Kentucky Derby and the Belmont Stakes.

Sports fans have long ditched the fancy hats for caps, except for Derby weekend in Kentucky.

Last year, a hat called the fascinator was all the rage.

The tiny hat owed its rise in popularity to the royal wedding, which took place just weeks before.

Hat maker Christine Moore says the fascinator is still hot, with about 35 percent of her customers still asking for it.

The hot trend this year?

The makers of a deer antler velvet product are suing Major League Baseball for libel.