Phil Jackson engaged with his girlfriend Jeanie Buss

 Jackson, 67, won two title as a player and added 11 rings as a coach, including five with the Lakers. Buss, 51, is the daughter of Lakers owner Jerry Buss and the sister of executive vice president Jim Buss. 

 Thursday that Jackson and Buss were engaged on Christmas Day.

Phil Jackson wasn’t busy coaching the Lakers again on Christmas. Instead, he was proposing marriage to Jeanie Buss, daughter of Lakers owner Jerry Buss.

Former LA Lakers coach Phil Jackson has finally popped the question to his longtime girlfriend Jeanie Buss -- after 12 years of dating -- but the real question ... could this affect the Zen Master's possible coaching gig with the Brooklyn Nets?

Our Lakers source tells us the engagement went down on Christmas day, but Jeanie -- daughter of Lakers owner Jerry Buss -- didn't reveal the ring until moments ago.

She posted a pic of the huge rock on Twitter with the caption ...  "Phil finally gave me that ring I wanted!"

Jeanie obviously has massive Lakers connections -- however Phil's currently being courted to take over as head coach of the Nets ... which might be a conflict of interest.

Hall of Fame coach Phil Jackson and longtime girlfriend, Lakers executive vice president Jeanie Buss, are engaged.

Buss announced the development on her Twitter account on Thursday night by posting a photo of a massive diamond ring on her left ring finger with the message, “Phil finally gave me that ring I wanted!”

Jeanie Buss told Forbes in 2011 that the couple had dated for more than a decade but that Jackson wasn’t particularly keen on the idea of marriage.

Buss wrote in her book “Laker Girl” in 2010 about Jackson’s impending exit as Lakers coach: “I know Phil and I are never going to be married. I don’t think I’ll ever be married again. Phil is planning to leave the Lakers at the end of next season and that means he will probably have to leave me as well. I know I cannot move to his retirement home in Montana, nor do I see him , 67, won two title as a player and added 11 rings as a coach, including five with the Lakers. Buss, 51, is the daughter of Lakers owner Jerry Buss and the sister of executive vice president Jim Buss. staying in a big city like Los Angeles. I am a working girl and the Lakers are my employer, which means my life is here.”