Tim Sherwood  has defended his criticism of Tottenham 's players after last weekend's defeat at Chelsea , claiming: “I’m their manager - not their babysitter."Spurs were thrashed 4-0 at Stamford Bridge following a series of calamitous defensive errors that led their rookie coach to question the mental toughness of his team.Ahead of Tottenham’s Europa League quarter-final first leg against Benfica, however, Sherwood defended his attack and suggested that his players should be strong enough to cope with with some flak.He told reporters: "You can't get out-fought and out-desired. I don't want to see that again. I won't tolerate less than 100 per cent desire.“I’m their manager, not their babysitter.”Sherwood, who replaced Andre Villas-Boas as Spurs boss on an 18-month contract in December 2013, admits his future at White Hart Lane remains up in the air, but is planning to remain at the club beyond his current deal."[There are] No guarantees," he said. "I've got an 18-month contract ... and expect to be here a lot longer than that."