If they had to pick their favorite team, LeBron and Jordan would probably say, Nike. Shoe and apparel made them richer than NBA teams did, gave them a chance to become billionaires. When a player picks a destination as a free agent, they'll get some estimates - how much we project you'll make if you play in LA or NYC compared to Indiana or Charlotte. Yet another advantage the Knicks squander away.
Alonzo Mourning had the same attitude; Nike was his team. But as players don't choose where they get drafted to, Mourning landed in Charlotte as a rookie. The player and team decided to make a splash and maximize his status in the state, so they put out an ad in the newspapers, congratulating the Hornets on drafting Alonzo. It caught people's eyes, that's for sure.
1992 was a rough year for the economy, so people weren't enthusiastic about the comparison between losing their jobs and homes with the possibility of cheering the no.2 pick playing for the Hornets. (we, unfortunately, didn't care about the environment as much back then) The team started receiving calls from fans and ticket holders who complained about the ad. The only explanation +they could offer was that they didn't place the ad; Nike did.
Mourning didn't learn a lot about PR from this experience. A few years later, he was asked about his loyalty. When asked does he work for the Hornets or Nike, Alonzo had no doubt.
“I work for Nike.”
Mourning didn't lie, and a lot of players share his sentiment. They may get traded or change a team in free agency; changing shoe brands is much rarer. They have more control in the relationship and make a lot of money once their career is over.