The MLBPA has certified Jay-Z and two other Roc Nation Sports execs to represent baseball players in contract work with MLB clubs. The union also approved Roc Nation Sports President Juan Perez and VP Rich Kleiman after reviewing their applications since April. The MLBPA is the second major sports union to certify Jay-Z to represent players in contract work, as the NBPA certified Jay-Z and Perez late last week. Jay-Z launched Roc Nation Sports on April 1 with the intention of creating a full-service sports agency to represent players in the major sports in marketing and playing contract work as well as brand-building. Anyone can represent athletes for marketing, but in order to negotiate playing contracts, agents must be certified by the unions that represent players in the various pro leagues. NBPA rules do not allow owners of NBA clubs to become certified player agents, and reports conflict over whether Jay-Z has sold his less than 1% interest in the Nets (Liz Mullen, SportsBusiness Journal). ESPN.com’s Darren Rovell cited a source as saying that Jay-Z as of yesterday “had not sold his small ownership share” in the team. But industry speculation is Jay-Z “might be able to sign players as long as he agrees to pass off his share of the Nets in the near future.” The first NBA player Jay-Z is “expected to sign is Oklahoma City Thunder star Kevin Durant, who told his agent, Rob Pelinka, in recent days that he would sign with Jay-Z.” Durant has not commented publicly (ESPN.com, 6/19).