"It said, 'To whom it may concern, Charles couldn't be at work because his daughter had to have a heart transplant,'" Tillman recalled.
Tillman has missed assorted training camp practices and offseason workouts, and revealed Friday at Children's Memorial Hospital that the reason for his absences was the plight of his infant daughter, Tiana. She had a form of cardiomyopathy in May, which eventually required a heart transplant.
On July 29, six days into training camp, Tiana Tillman became the first person in Illinois to benefit from the use of a device called the Berlin Heart, a small pump located outside the body but connected to the heart. The device is run by a laptop computer and works by helping the right ventricle of the heart pump blood to the lungs, and the left ventricle to pump blood to the body.
It works as a bridge to a transplant and allows those awaiting transplants more time until an organ becomes available.
Tiana, who is now 6 months old, eventually underwent a heart transplant and was released from the hospital Monday.
"By her being on that Berlin Heart, it saved her life," Tillman said. "It bought us more time. You can live on a Berlin Heart over 365 days while we were waiting on a heart."
Tiana had an enlarged, weakened heart that was beating over 200 times a minute when she was airlifted to the hospital in May while the Bears were going through off-season workouts.
Tillman and his wife, Jackie, were with their daughter around the clock, but eventually he had to report for July training camp.
"I tried to not let this overcome me because I knew I had a job to do and I had a season coming up," Tillman said. "I'm not going to lie -- it was hard. Some days I would sit in my room and just think, 'what am I doing here,' I would feel guilty for being at work and not being (at the hospital) with my kid. I had those days."
The Bears gave the sixth-year veteran plenty of leeway with practice.
"As far as camp and football and things like that, I told Charles if he felt like coming to practice, come to practice, but take care of his family and go from there," Smith said. "We're just glad that it seems like it's going to have a happy ending.
"You talk about real men and being a father and husband, I've had a chance to see him go through a lot of different things and he just stepped up to the plate."
Tillman called a press conference at the hospital where the surgery was performed for several reasons, including to clear up why he had been missing practices.
"My wife would get on these blog sites and stuff like that and people were wondering why I wasn't at practice," Tillman said. "Someone said I was getting traded for Brett Favre. One blog said I hit my wife. And one blog said I got arrested for drinking and driving. It was a bunch of crazy stuff."
Tillman also wanted to publicize the Berlin Heart, and he stressed the need for organ donation.
"I think probably the toughest thing that I had to battle with, and I still battle with it now, is that I knew in order for my daughter to live, another kid had to die," Tillman said. "I struggled with it and struggled with it.
"The biggest thing that I got out of it is you're taking something negative and making it into a positive instead of having just two negatives."
He urged everyone to become an organ donor.
"It saved my daughter's life," he said. "One person can save 20 lives."