LeBron James is reportedly "frustrated and concerned" with the Cleveland Cavaliers, specifically with team owner Dan Gilbert's ability to assemble a roster that can better compete with the defending champion Golden State Warriors.

LeBron was clearly not happy when the Cavs failed to bring back general manager David Griffin, but that's not the only reason he is reportedly miffed with the organization this offseason.

Jeff Zillgitt of USA Today reports

"Expecting an aggressive offseason approach that would close the gap on the champion Golden State Warriors, James soon found his anticipation and optimism diminished after Cavaliers owner Dan Gilbert dismantled the front office, declining days before the draft and free agency to bring back general manager David Griffin and vice president of basketball operations Trent Redden.

"Gilbert's decision left the Cavs without the franchise's top two front-office execs at a critical time, and it left James frustrated and concerned about the team's ability to put together a roster that can better compete with Golden State, the person with direct knowledge of James' thinking told USA Today Sports."

Additionally, Zillgitt mentions,

 "Further exacerbating James' frustration is the Cavs were close to making a deal for then-Chicago Bulls All-Star Jimmy Butler the day Gilbert decided to mutually part ways with Griffin and Redden."

LeBron is set to become a free agent after the 2017-18 season and rumors are already swirling that he's interested in forming a super-team elsewhere.