Jason Collins is good for the NBA: Magic Johnson

Magic Johnson: Jason Collins is smart

Jason Collins, the first openly gay player to play in the National Basketball Association, got support on Thursday from one of the most accomplished athletes in the game's history: Five-time NBA champion Earvin "Magic" Johnson.

Collins revealed his sexuality after last year's regular season, making him the first openly gay athlete in any of the United States' four major professional sports leagues. He was not signed for the NBA's 2013-14 season, however, until the Brooklyn Nets offered him a 10-day contract earlier this week.

"That was great," Johnson said on CNBC's "Power Lunch." "It was great for the Brooklyn Nets, great for Jason, because he just wanted to play basketball."

Johnson, a three-time Most Valuable Player and 12-time All-Star, called Collins "smart" and noted that he had attended Stanford University. He characterized him as a "big body" on the court who can help win games by rebounding and screening setups.

Though Collins, 35, played only 11 minutes and went scoreless in his Net debut Monday, he does appear to be boosting business. His "Collins 98" jersey is the league's most popular one, even outselling shirts of the NBA's global superstars.

"I think that was a great move for the NBA, and for Jason and for gays," Johnson said.

Magic Johnson: Howard Schultz taught me a lot

Separately, Johnson said that Gov. Jan Brewer did the right thing in vetoing SB 1062, the Arizona law that would have let businesses refuse service to gay and lesbians on the basis of religious freedom. Had the bill become law, Johnson said, Arizona could have lost a lot of business and risked the National Football League's moving next year's Super Bowl elsewhere.

(Read more: Arizona governor vetoes religious freedom bill)

Speaking of business, Johnson said former Los Angeles Lakers owner Jerry Buss first got him interested in entrepreneurship.

Johnson also praised Starbucks CEO Howard Schultz for being one of his most important mentors, saying that he taught him everything—from the bottom line to branding and the importance of customer service. The two have partnered to bring Starbucks into urban locations frequently overlooked by corporations.

"Minorities love Starbucks, too, like everybody else," he said.

—By CNBC's Drew Sandholm. Follow him on Twitter @DrewSandholm.