Ailing San Antonio Spurs drop fourth in a row

SAN ANTONIO (Reuters) - NBA leaders San Antonio are mired in their longest losing streak of the season after a 100-92 loss to the Portland Trail Blazers on Monday without three key players earned the Spurs a fourth consecutive defeat.

Tim Duncan, Manu Ginobili and Tony Parker were all sidelined with injuries as the Spurs (57-17) saw their lead in the Western Conference trimmed to three and a half games over the surging Los Angeles Lakers.

While the losing streak will be a worry for the Spurs, of greater concern is the team's injury list with next month's playoffs fast approaching.

Parker (knee) and Ginobili (left quad) missed their first game and are expected to be back soon but the timetable for Duncan's return is unknown after he suffered an ankle injury last week.

Starting forward Antonio McDyess was also given a rest on Monday with the playoffs on the horizon.

The Spurs' next game is against Boston on Thursday. (Writing by Jahmal Corner in Los Angeles; Editing by Peter Rutherford)