BIRMINGHAM, England — Maria Sharapova's Wimbledon preparations received a setback Saturday in a 6-4, 6-4 loss to Li Na of China in the Aegon Classic semifinals.

The Russian served erratically to drop to 5-1 against the 20th-ranked Li. The former No. 1 player had been out for 10 months with a shoulder injury before returning to action last month at the French Open.

"After such a long layover, every match and every situation is a different test to the body," said Sharapova, the 2004 Wimbledon champion.

"I still felt like I had many chances in this match, but I have played five matches in the last six days and after that you just hope you wake up with that intensity you need. Against her you need that."

Li will play Magdalena Rybarikova of Slovakia, who defeated Sania Mirza of India 3-6, 6-0, 6-3.

Sharapova's serve — revamped to prevent injury — lacked rhythm and conviction and she was broken six times.

She dropped serve to trail 4-2 in the first set after missing a forehand before recovering to trail 5-4. However, she was broken again to lose the set.

Sharapova broke to lead 2-0 in the second set, but then lost four straight games and never recovered.

She will spend next week practicing at Wimbledon, with the tournament starting June 22.