LeBron James was stunned to learn of Magic Johnson's decision to step down as the Los Angeles Lakers' president of basketball operations, a source with knowledge of James' thinking told ESPN's Ramona Shelburne.

But despite Johnson's abrupt resignation, James stands behind Lakers owner Jeanie Buss and the organization, the source told Shelburne.

Johnson sent shockwaves through the Lakers' franchise Tuesday night when, in a teary-eyed announcement before the team's season finale, he announced his "difficult decision."

Johnson said he had not informed Buss or general manager Rob Pelinka of his decision before talking to reporters. He later told ESPN's Rachel Nichols that he didn't tell Buss first because he was afraid she would have talked him out of it.

Johnson took to Twitter on Wednesday morning to thank Buss, Pelinka, coach Luke Walton and the rest of the Lakers' franchise.

Thank you to Lakers owner Jeanie Buss, General Manager Rob Pelinka, Coach Luke Walton, the Lakers players & the entire basketball operations staff for the tremendous opportunity to serve as the President of Basketball Operations for the @Lakers. I will always be a Laker for life.

— Earvin Magic Johnson (@MagicJohnson) April 10, 2019

A big thank you to Jesse Buss, Joey Buss, Ryan West, Sam Usher, Marshall Rader, and Elaine Shen.

— Earvin Magic Johnson (@MagicJohnson) April 10, 2019

I have the best assistant in the world, Natalie Wilson. Thank you Natalie Wilson, Shane Jenkins, and Desiree LeSassier for working with me for many years and joining me at the Lakers.

— Earvin Magic Johnson (@MagicJohnson) April 10, 2019

Another big thank you to Lakers Executive Linda Rambis and her husband, Laker great, Kurt Rambis.

— Earvin Magic Johnson (@MagicJohnson) April 10, 2019

League sources told ESPN's Adrian Wojnarowski that Johnson and Pelinka visited with James and his agent, Rich Paul, on Saturday. Walton also participated in the meeting, a source told Shelburne.

Johnson offered no indication that he was on the brink of leaving the team, sources said. Johnson said he did not tell James about his decision to leave before making his announcement, either.

The Lakers finished the season 37-45 and went 35-47 last season, putting the job security of Walton, the third-year coach, in jeopardy. The team has not made the playoffs since 2013.

Walton has two years remaining on his contract, but only next season is guaranteed, a source told Wojnarowski.

When asked by Nichols if he was preparing to let Walton go, Johnson said, "Yeah, I was preparing to make that decision."