WIMBLEDON, England -- Wimbledon champion Venus Williams might quit tennis soon, her father Richard said Wednesday.

Richard Williams, speaking at the launch of a television documentary on his family, said his daughter had a lot of business interests and pointed out her $40 million contract with Reebok was for three years rather than five.

"I don't think she'll be around for a very long time," he said. "I doubt it will be a long career for her.

"She can make a lot more money out of (tennis) rather than in tennis."

Venus Williams, 21, plays third seed Lindsay Davenport in the semifinals on Thursday, a repeat of last year's Wimbledon final.

Richard Williams, who was close to tears, also said his younger daughter Serena had flown home Wednesday and that she was feeling "pretty sick."

Serena was knocked out in the Wimbledon quarterfinals on Tuesday by fellow American Jennifer Capriati and said later she had been ill for four days and unable to keep her food down.

Her father said she had seen three doctors while she was in London.