Among LinkedIn's 300 million users - lawyers, doctors and financial consultants - is a new profession: pro athlete.

Dan Black, a professional baseball player who played for both the Miami Marlins and Chicago White Sox organizations, created an account at the networking site a few years ago in preparation for his next career: coaching.

"It's an easy way to connect with current college coaches," he wrote in a LinkedIn message. "Not necessarily to talk to them yet but to begin the process. Baseball is a small community on a grand scale."

Making connections on LinkedIn has worked out for the 29-year-old Indianapolis native. The platform helped him sign with Diablos Rojos del Mexico, a professional baseball team in the Mexican League. He connected with a scout to whom he hadn't spoken in a couple of years, and that scout put him in touch with the team.

Black's case is hardly rare.

Over the past couple of years, baseball, football and basketball players have been flocking to LinkedIn, where they create profiles highlighting their skills and experience for prospective employers. During and after their playing days, athletes use the site to better transition to their next endeavor.

NBA legend Shaquille O'Neal and six-time MLB All Star and former Pittsburgh Pirates slugger Jose Bautista each have a LinkedIn account. Pittsburgh Steelers linebacker Arthur Moats, safety Mike Mitchell and wide receiver Isaac Blakeney are also registered users. LinkedIn declined to state how many pro athletes use the site.

Only about 10 percent of minor league baseball players make it to the majors, which could explain why MLB-hopefuls are seemingly the largest athlete demographic on the site.

But no matter the sport, athletic careers are often short-lived. The average length of an NFL career is only 3.3 years, according to the NFL Players Association, and it's not much longer in the NBA (4.8 years), NHL (5.5) and MLB (5.6).

That's why athletes use LinkedIn while still playing - to make their transitions to the workforce a little smoother, said Marc Ganis, president of the Chicago-based sports business advisory firm Sportscorp Ltd.

Sixty-percent of former NBA players are broke within five years of retirement, according to Sports Illustrated. By the time they have been retired for two years, 78 percent of former NFL players have gone bankrupt or are under financial stress.

Shopping excessively, blowing thousands on top-line dinners and supporting family and friends are among the reasons athletes go broke, experts say. Athletes also must pay taxes to every state in which they play or train. Often, they sign lucrative contracts out of high school or college with little financial experience.

"Most athletes were trained in high school and college to be athletes, to the exclusion of almost all else," Ganis said. "They're predominantly young men who have no other skills, no other training."

It's one of the reasons the NFLPA guides rookies and superstars alike on how to effectively use LinkedIn and other social media platforms. Players' associations run seminars at major universities across the U.S. and many NFL clubs offer programs in which players can learn strategies to use social media effectively, said the NFLPA's director of communications Carl Francis.

Before LinkedIn, athletes relied on word-of-mouth to stay in touch with former players, coaches and scouts. Now, the NCAA and universities are working to do their part, too.

Last year, the NCAA launched, "After the Game Career Center," an online portal full of job listings and networking advice for current and former collegiate athletes.

On an individual level, Division I programs are adding support staff, including academic advisers, who work exclusively with athletic teams. They provide tutors, help with internship searches and offer time management strategies.

Erik Forgione, an infielder for the Pirates' Class-A Short Season affiliate West Virginia Black Bears, aspires to start a nonprofit organization when his playing days are over. He uses LinkedIn to connect with nonprofit leaders and generate ideas.

Tyler Filliben, an infielder for the Pirates' Class-A affiliate West Virginia Power, was required to create an account for a class at Samford University. The management and economics double major then began reaching out to people in the financial industry, where he plans to work after baseball. For the past two winters, he has interned at financial firms.

"In college, I didn't know how baseball was going to work out," Filliben said. "Marketing myself in a professional manner was an important thing. I knew if baseball didn't work out, I'd have to leverage my degree."

"Employers know I'm not just one dimensional," he added. "I want to have a life after baseball and know what to do."

Filliben met his agent, Bryan Symes, through LinkedIn last offseason. Symes, a Wisconsin-based employment attorney, has connected with athletes on the site since around 2012, where he has found a handful of his 20 minor league baseball clients.

"Not everybody makes it to the majors," he said. "(LinkedIn) just makes good sense because it is a primary social media platform. They can create a presence so if it doesn't work out in baseball, they have a plan B."