Photos show what the world's top tennis players looked like when their careers started

Serena Williams in 1997 (age 16).

Serena Williams now (37).

Roger Federer in 2000 (age 18).

Roger Federer now (37).

Novak Djokovic in 2005 (age 18)

Novak Djokovic now (32).

Maria Sharapova in 2002 (age 15).

Maria Sharapova now (32).

Rafael Nadal in 2004 (age 18)

Rafael Nadal now (33).

Venus Williams in 1997 (age 17).

Venus Williams now (39).

Andy Murray in 2002 (age 16).

Andy Murray now (32).

Angelique Kerber in 2008 (age 20).

Angelique Kerber now (31).

Victoria Azarenka in 2005 (age 16).

Victoria Azarenka now (29).

Juan Martin del Potro in 2006 (age 18).

Juan Martin del Potro now (32).

Stan Wawrinka in 2003 (age 18).

Stan Wawrinka now (34).

Jo-Wilfried Tsonga in 2004 (age 19)

Jo-Wilfried Tsonga now (34).

Caroline Wozniacki in 2006 (age 16).

Caroline Wozniacki now (28).

Nick Kyrgios in 2014 (age 19).

Nick Kyrgios now (24).

Now, check out the amazing photos captured throughout Roger Federer's career...

24 gorgeous photos of Roger Federer playing tennis >