Venus Williams says that since she was diagnosed with Sjögren's Syndrome in 2011, she has learned to cope with the challenges of playing pro tennis while battling an autoimmune disease.

The 33-year-old is scheduled to play the tournament in Auckland this week. The seven-time Grand Slam champion only played 11 tournaments in 2013.

"I've learned a lot," Williams told reporters. "There is no manual on how to be a professional athlete with an autoimmune disease. It is something that I have tried to make into a positive in my life. It's kept me going. I've been through this and never gave up so obviously I want to keep going."

Williams hasn't reached the final of a Grand Slam since the 20090 Wimbledon, but still believes she has a bright future.

"I have some goals but for me it is about playing well [and] every match leads to the next match,” she said. “In my career, a lot of the losses have been important too because I learned a lot from those losses and they made me better. So, yeah, I want to win majors and I might have some losses but I will learn and it builds character."