Maria makes another comeback

Defending champion Maria Sharapova makes her first appearance since Wimbledon at the San Diego Classic this week, once again testing a long-standing shoulder injury.

The world No.2, who beat Kim Clijsters in the 2006 hard court final, has been dogged by the injury problem since the (northern) spring.

But a pain-killing injection helped her to the French Open semi-finals and a Wimbledon fourth-round loss to Venus Williams.

Following the wet fortnight at the All England Club, the 20-year-old Russian had a precautionary scan and controversially pulled out of Russia's Fed Cup semi-final win over the United States.

Despite failing to win a trophy so far this season, and with her US Open title defence approaching, Sharapova is unworried.

"I'm 20 years-old, I've won two Grand Slams. I've been No.1 in the world," she said today (AEST).

"I've got plenty more years to either win matches or find confidence."