"Until we get it cleared up, I won't be with the team," Lee said. "My daughter's lost some vision in one eye. Until we find out more -- right now we have to go through some more tests.
"We just ask for everyone's prayers," Lee said. "We need a miracle. We need your prayers. We need everyone to believe she's going to be OK."
This has been a difficult season for Lee, 31, the defending National League batting champion who broke his right wrist April 19 in a freak collision with Rafael Furcal. Lee missed two months, and then had to go back on the disabled list to give his wrist more time to heal. He was batting .345 in 15 games since his return in late August.
None of that matters now.
"You break your wrist and you think that's a big deal, and then something like this happens and it slaps you in the face as to what really matters," Lee said. "It's all about your loved ones, and all about your family. We just ask for your prayers."
Lee addressed his teammates Sunday before leaving.
"It's tough, especially when you have kids involved," Cubs manager Dusty Baker said. "You wonder why, and sometimes there are no answers. We just have to pray for him."
"It's been a tough year, some strange things have happened this year to say the least," Baker said. "It's one thing after another. Every time there's one thing that you think is the most serious, there comes an even more serious one. You pray and hope she'll be all right and give them strength."
For example, Cubs pitcher Glendon Rusch remains in the hospital after a blood clot was discovered in his right lung last Tuesday.
Jada was being treated in Chicago. She is Derrek and Christina Lee's only child.
"My experience is you have to play for something in these situations," Baker said. "In these situations, you have to play for a sick person or a grandmother or your mom or your dad. You play for D-Lee, you play for D-Lee's daughter -- you've got to find something to play for."
"It's usually not bad during the games," Baker said. "It's worse when you go home after the games. It's like anybody -- while you're at work it's cool. When you get off work, everything comes back down. You've got to play. You've got find a reason to play."
The Cubs have 13 games remaining, including Sunday's series finale against the Reds.