Dick Advocaat warned his side they face relegation if they don't improve . Sunderland were thumped by Crystal Palace at the Stadium of Light . Blacks Cats boss Advocaat has admitted he is worried by relegation . Sunderland are 51 points clear of the Premier League relegation zone .
Dick Advocaat warned his side they face relegation if they don't improve . Sunderland were thumped by Crystal Palace at the Stadium of Light . Blacks Cats boss Advocaat has admitted he is worried by relegation . Sunderland are three points clear of the Premier League relegation zone .