Serena Williams will ring in 2019 with a mixed doubles match against Roger Federer

Washington Post -

Washington Post—Williams, who is highly unlikely to play again this year, is already thinking about Australia and the Hopman Cup, where she'll partner with Frances Tiafoe.

Roger Federer, Serena Williams set for Hopman Cup team event. Serena Williams and Roger Federer have committed to play the Hopman Cup mixed teams event in late December while former Australian Open champion Angelique Kerber and Alexander Zverev will represent Germany.