Tommy Robredo rose nearly 100 spots in rankings in 2013.
Jose Altur tabbed as replacement for 2014.
Nadezhda Ilyina perished in a car crash December 7.
NBC comedy mocks Russia's anti-homosexual stance
Chris Evert: 59 and feeling fine
Appointment seen as US protest to Russia's anti-gay laws.
John McEnroe, Jimmy Connors, Pat Cash and Ivan Lendl to reconvene.