The 79-year-old was admitted Thursday to Cedars-Sinai Medical Center, where he is undergoing chemotherapy.
There are some reports that he only has a few days to live.
Buss bought the Lakers back in 1979 and quickly built the team into a champion. In fact, the team has won 10 championships under his ownership. He has had a huge impact on the game, certainly building the Lakers into one of the greatest sports franchises in NBA history.
"He knows exactly what he wants to do and how he wants to construct the ball club and he was extremely, extremely smart in going about it. It's very rare to find that kind of owner that can really, seemingly not make any mistakes. It's pretty impressive," said Kobe Bryant.
Other players reacted to Buss' illness online.
"Dr. Buss is an important part of the Laker family so I hope his stay at the hospital is short and he has a speedy recovery. #JerryBuss," five-time champion Kareem Abdul-Jabbar posted on his Twitter account.
Three-time champ Shaquille O'Neal also posted on Twitter, "Dr. Jerry Buss, thinking about u & wish I could be there, get well soon. I can't wait to see you on 4/2/13. #LoveYou #Lakers"
"4/2/13" is a reference to when O'Neal's jersey will be retired by the Lakers.
There is no official comment on Buss' condition from the Lakers.
Buss has been hospitalized several times in recent years, including a stint last July for dehydration. He was treated for blood clots in his legs in December 2011.
The Associated Press contributed to this report.