Former U.S. striker Charlie Davies retires at 31

WATCH: Former USMNT striker Charlie Davies announces retirement (0:54)

After an 11-year professional career, watch Charlie Davies' heartfelt message to fans as the former U.S. national team forward officially announces his retirement. (0:54)

Former United States striker Charlie Davies announced his retirement on Friday at age 31.

Davies was out of contract after spending the past two years with the Philadelphia Union, though he only made three appearances off the bench in 2017.

"After careful thought and with a very heavy heart, I've decided to retire from playing professional soccer," Davies said. "Ever since I was six years old, I dreamed of becoming a professional soccer player and it has been so much more than I ever could have imagined."

Davies was a crucial part of the U.S. attack in the lead-up to the 2010 World Cup, but his promising career was derailed by injuries suffered in a 2009 car accident that killed another passenger.

Davies broke two bones in his right leg and his elbow, nose, forehead and eye socket, while also suffering a ruptured bladder and bleeding on his brain.

He was able to get back on the pitch in 2011 on loan with D.C. United and even returned to his French club Sochaux, but he never played for the national team again.

He moved to Randers in Denmark the next year before signing full-time in MLS with the New England Revolution, only to be dealt another setback when he was diagnosed with a rare form of cancer in 2016.

"I've loved every second of my time on the field even the desperate lows of injury and cancer that have made the highs all that much sweeter," Davies said.

"I've loved the friendships, the competition and I've loved all the amazing people on both sides of the fence."