Rojer was playing his first Grand Slam final while Groenefeld won the mixed doubles title at Wimbledon with Mark Knowles of the Bahamas in 2009.
''I gained a friend this week. I lost one, because I had to tell some other player that I'm not playing with her,'' Rojer said. ''So I hope she understands, especially now. But I apologized like 18 times to her.''
Rojer and Groenefeld were teaming up for the first time.
''Actually, I was asking around,'' Groenefeld said. ''No one wanted to play with me, and then he said yes.''