CLEVELAND -- Cavaliers owner Dan Gilbert insists he has moved on from LeBron James. But on to what?

Gilbert has reportedly enlisted a law firm to investigate the circumstances leading to James leaving Cleveland to sign with the Miami Heat this summer.

Yahoo! Sports reported on Wednesday that Gilbert has paid hundreds of thousands of dollars to a Midwestern law firm to investigate suspicions that the Heat broke NBA tampering rules while pursuing James, who left the Cavs after seven seasons to join fellow stars Chris Bosh and Dwyane Wade in Miami.

League sources told ESPN The Magazine's Chris Broussard that members of the Cavs' front office tried to convince Gilbert not to pursue tampering charges, but Gilbert is so incensed by James' decision that he believes it's worth it even if a draft pick is the only reward.

The timing of the report is interesting since James will return to play in Cleveland for the first time on Thursday night, in what promises to be a hostile Quicken Loans Arena.

On Tuesday, Gilbert, who was highly critical of James following the superstar's televised announcement in July, was asked about his emotions heading into the reunion with the two-time league MVP.

"I'm over it," he said. "I really am. That's the truth. I let it all out in about 24 hours. I just think we have such a great core and a great coaching staff. We have a lot of opportunities with the trade exception and the draft. I feel good about this team."

Team spokesman Tad Carper said Wednesday night the Cavaliers are declining comment on the Yahoo! report, which citing anonymous league sources, says Gilbert plans to present NBA commissioner David Stern with a detailed case with the hopes of launching a tampering investigation.