WATCH: Roger Federer warms up with young cancer survivor at U.S. Open

Awesome moment between Roger Federer and a young cancer survivor.

Before Roger Federer took the court against Philipp Kohlschreiber at the U.S. Open Monday night, he warmed up on the practice court with a young cancer survivor. 

Mark Krajekian considers Federer his hero, according to ESPN. With hundreds of people watching, Krajekian and Federer rallied on the practice court prior to Monday's fourth-round match. 

Here's an angle from the stands: 

If Kohlschreiber goes for the lob on Monday, we can assume Mark Krajekian gave him the inspiration.