LOS ANGELES — Los Angeles Lakers guard Steve Nash has been ruled out for the season because of a back injury, putting the two-time NBA MVP's career in doubt.

The Lakers and Nash announced their joint decision less than a week before the start of what would have been the 40-year-old Nash's 19th NBA season. He played in only 15 games last season with nerve root irritation, but hoped for a comeback season after several months of rehabilitation.

Instead, the Canadian point guard played in just three preseason games before feeling more back pain. He then strained his back while carrying bags several days ago.

Nash, the NBA's oldest active player, is due more than $9 million this season.

RALEIGH, N.C. — An alarming lack of institutional oversight at the University of North Carolina allowed an academic fraud scandal to run unchecked for nearly two decades.The latest investigation found that university leaders, faculty members and staff missed or just ignored flags that could've stopped the problem years earlier. More than 3,100 students — about half of them athletes — benefited from sham classes and artificially high grades in the formerly named African and Afro-American Studies department in Chapel Hill. A report by former U.S. Justice Department official Kenneth Wainstein indicates that the bogus classes ended in 2011.

SINGAPORE — Serena Williams rebounded from the worst loss of her professional career to rout Eugenie Bouchard 6-1, 6-1 in the WTA Finals.Williams was humbled by Simona Halep the previous day, when the 18-time Grand Slam champion won only two games. Williams improved to 2-1 in round-robin play. The American will have to wait until Friday's match between Halep and Ana Ivanovic to know if she is through to the semis.