The NBA blocked Kevin Garnett’s bid to purchase a minority stake in Italian soccer club AS Roma.

Roma is led by Celtics minority owner James Pallotta.

“If you enter into a business agreement with the owner of a team that doesn’t involve playing service, there are potential problems,” a league source said. “Maybe not in this case. But there is a chance of, say, making a contract a lot larger.”

In April, LeBron James obtained a small stake in Liverpool FC, which is owned by Boston-based Fenway Sports Group.

“With LeBron, there is no tie-in whatsoever, so it’s a different deal,” the source said. “It’s like having a business relationship with Nike. We make it simple — you can’t have a business deal with your team, or any other team, because there is the possibility of an underhanded deal there. It’s pretty clear-cut.”