Seven-year-old Ian Rosenbaum first met Letang when he attended Pittsburgh Penguins practice after getting diagnosed with T-cell leukemia at UPMC Children's Hospital of Pittsburgh.
Since then, the two have built a friendship, and even got matching No. 58 hockey jerseys during a recent fundraiser.
Now, Letang has reached into his own pocket and is making a $58,000 donation to help cover Ian's medical expenses.
"It has been amazing, overwhelming," Ian's mother, Joelle, told the Pens Inside Scoop. "For Ian to go through this and for someone like Kris to take time for our child is simply amazing."