Beginning in 2002, Greenberg formed and led an ownership group that purchased the Double-A
Eastern League's
Altoona Curve, a minor league baseball team in Pennsylvania. For seven seasons (2002–2008), Greenberg acted as managing partner and president of the team. He is credited with helping the organization set fan attendance records, while continually re-investing money to improve the Blair County Ballpark, which resulted in national recognition of the franchise as one of the most innovative teams in professional sports. Due in part to Greenberg's contributions to the baseball industry and the local community, the organization was awarded the John H. Johnson Presidents Trophy in December 2006, given to the top franchise in all of Minor League Baseball for overall quality and performance. During Greenberg's tenure as managing partner and president, the franchise won several other awards, including the
Larry MacPhail Award, presented in December 2004 by the Minor League Baseball association as the top franchise in all of Minor League Baseball for marketing, promotions, and community service and the Bob Freitas Award in November 2006, awarded by Baseball America as the top Double-A franchise in Minor League Baseball. Greenberg was also a finalist for the Ernst & Young Entrepreneur of the Year in 2006 as a finalist in the Western Pennsylvania and New York Region for ownership and management of Altoona Curve and State College Spikes. Greenberg and his ownership group (Curve Baseball LP) sold the team to the Robert F. Lozinak family in 2008. While continuing to manage and operate the Altoona Curve, Greenberg and his investment group also purchased the former New Jersey Cardinals. He immediately relocated the franchise to
State College, Pennsylvania, in collaboration with
Penn State University. Greenberg worked with the university to create the area's first-ever professional sports franchise, the
State College Spikes, which began play in the
New York-Penn League in 2006. Greenberg's hard work associated with the unique relationship between the Spikes and the university has become a model in the industry for facilities, shared by a major university and a professional sports franchise.
Medlar Field at Lubrano Park was the first ballpark in America LEED-certified for leadership in environmental and energy design. In conjunction with Major League Baseball's reorganization of Minor League Baseball following the 2020 season, Greenberg partnered with MLB and other owners in the creation of the new MLB Draft League, which serves as a showcase for draft-eligible players. The Spikes became a founding member of the MLB Draft League and have continued to flourish. Greenberg took over as president and managing partner of the
Myrtle Beach Pelicans in June 2006 when he and a group of investors purchased the Minor League Baseball team. Greenberg worked to enhance Pelicans Ballpark in Myrtle Beach, making it one of the most fan-friendly venues in Minor League Baseball. Greenberg and his group of investors immediately invested $2.5 million on a wide array of upgrades to enhance Pelicans ballpark, including the opening of Pelican's Beach, dubbed "the only baseball-front beach in America". The Pelicans also reached several attendance milestones, including setting the team's all-time franchise attendance record in 2008 and the all-time average attendance record in 2009, a record that has since been broken in 2014 and again in 2015. In 2025, the Pelicans surpassed the franchise record for attendance in a single game, welcoming 6,600 fans to the ballpark on July 4th. In December 2015, the Pelicans won Baseball America's Bob Freitas Award as the top Class A-Advanced franchise in Minor League Baseball. As of 2024, Pelicans Ballpark has won
Stadium Journey Top Gameday Experience for Single-A Baseball Award a remarkable six seasons in a row. In August 2014, Greenberg led an ownership that purchased the
Frisco RoughRiders, the
Double-A affiliate of the Texas Rangers. The new ownership group has spearheaded numerous major franchise improvements, from a completely new team identity to massive additions and upgrades to Riders Field, including a giant 2,763-square-foot HD video board and nearly 2,500-square-feet of new outfield-wall LED ribbons, a state-of-the-art sound system, a completely redesigned and modern video control room, an open-air in-park sports bar, a relocated and expanded team store, known as "Riders Outpost", improved food service and menu, and a complete overhaul of in-game entertainment. The improvements earned the Riders and the City of Frisco "Best Ballpark Renovation" of 2015 by
Ballpark Digest in the under $6 million category. In 2016, Greenberg and the franchise innovated, creating the one-of-a-kind Lazy River beyond the right-field wall. Opening on June 9th, 2016, the 174-foot Lazy River is the largest known water feature at a professional sports venue in the world. The Lazy River has since become an iconic attraction at the stadium and has led to the ballpark being featured on national media outlets, such as ESPN, MLB Network, CBS Nightly News and more.
Texas Rangers Rangers Baseball Express, led by Greenberg and including former baseball great Nolan Ryan, won an auction to purchase the
Texas Rangers on August 5, 2010, after hours of courtroom bidding. Greenberg described it as "a painful process ... it dispelled any notion that we haven't earned our way. We will deliver on our promises. And we want to deliver a championship." The two parties bidding for the franchise were the Ryan/Greenberg group and a group led by
Dallas Mavericks owner
Mark Cuban and Houston businessman
Jim Crane. Hours of delays and bidding resulted in a final sale price of $593 million, $385 million cash and $208 million in assumed liabilities. Rangers Baseball Express, LLC, had earlier signed a definitive agreement to purchase the Texas Rangers team from Tom Hicks and Hicks Sports Group on January 23, 2010.
The Dallas Observer said in April 2010 that Greenberg "has the money and moxie to lead the Texas Rangers back to relevancy and into the playoffs." Greenberg served as managing partner and CEO of the Rangers, while Ryan continued in his role as team president. Greenberg's vision for the team included both a dedication to being the best at every aspect of the operation and a focus on creating a highly entertaining fan experience at the ballpark. Greenberg said, "[W]e're here to win. We love baseball. We have an unbelievably deep emotional attachment to the Rangers and Rangers' fans. We're going to do everything we can to win." Rangers
General Manager Jon Daniels has praised Greenberg for his personal connection to the fans, noting "He's just a normal guy. Jeans and T-shirts. He's really in tune with fans and knows how to have his finger on the pulse of what they want. He's very impressive. He wants revenue, make no mistake about that. But above and beyond that comes winning." The comments made by Greenberg followed an incident in Game 3 of the ALCS when Kristen Lee, wife of Texas Ranger pitcher
Cliff Lee, told the media about the treatment her and other players' wives received by fans at
New Yankee Stadium.
Misty May, wife of backup catcher
Matt Treanor, posted pictures on her Facebook page of Yankee fans spitting from the upper deck down into the section where her family and other Rangers fans were sitting. On March 11, 2011, Greenberg announced that he was stepping down as Managing Partner and Chief Executive Officer of the Texas Rangers and that he would be selling his interest in the Rangers and will no longer be associated with the franchise. Club president
Nolan Ryan assumed the title of CEO, overseeing all aspects of the Rangers operations on both the baseball and the business side. Previously, Greenberg had expressed interest in purchasing the
Dallas Stars in 2011 before the team was sold to
Tom Gaglardi. The sale of the Hurricanes to Greenberg would later fell apart and the team would be sold to
Thomas Dundon in 2018. ==Other sports interests==