The child was just 3 months old when doctors diagnosed her with a heart defect.
Tillman's daughter is now 6 months old. And doctors say without this experimental procedure, the little girl may not have made it.
Tillman says it soon became apparent one day back in May that his daughter had a serious medical problem. She was airlifted to Children's Medical Center, where doctors diagnosed the 3-month-old with cardiomyopathy, a condition that causes the heart to weaken and enlarge.
"I don't think I had enough time to cry because I was trying to be strong for my wife and other kid," said Tillman, a cornerback.
Tillman put his daughter, Tiana, on a list for a heart transplant.
"Your heart is the size of your fist. Her heart was probably the size of yours or yours, four times too big," Tillman said.
To keep her stable, one surgeon encouraged Tillman to try something new, an apparatus called the Berlin heart. Most of it sits outside of the body, helping the heart to pump blood. The patient can stay awake.
The Berlin heart is widespread in Europe, but has not been approved by the Food and Drug Administration. But the FDA has allowed what's called compassionate use of the device more than 100 times.
"The advantage of this device is that it provides better quality of life and strengthens patients before they receive their heart transplant," said Dr. Sanjay Kaushal, Children's Medical Center
"By her being on the Berlin heart, it saved her life. It bought us more time," said Tillman.
After two days on the Berlin heart. a donor heart became available. Tillman's daughter, now 6 months old, is recovering and went home Monday. He says he wants to raise more awareness about organ donation.
"I knew that in order for my daughter to live, another kid had to die," Tillman said. "I'm so grateful for what they did; they did a very noble thing."
Tillman started a foundation a few years ago to help chronically ill children. He says he now wants to include research on cardiomyopathy.
He also thanked the public for its support, as well as the Bears. He said one of the surgeons wrote a note to excuse him from practice. Coach Lovie Smith, who was there Friday, simply said the Bears wanted to help Tillman any way they could.