Serena Williams’s Practices Add a Wrinkle: A Top Men’s Player

Aly Song/Reuters

MELBOURNE, Australia — After 170th-ranked Christopher Eubanks made it through the qualifying draw of a Grand Slam event for the first time last week, many of his friends from back in Atlanta began to grasp how far his career had come.

It was not because of the three qualifying matches he had won, but rather because of who joined him for a practice before the Australian Open began: Serena Williams.

“Some of my friends who don’t really know tennis were saying, ‘If he’s hitting with Serena, he must be pretty good,’ ” Eubanks said.

His session with her was part of a new strategy for Williams, who is training with some of the best current players from the men’s tour to raise the…