He lost a World Championship qualifier 9–10 to journeyman Joe Delaney in 2007. This loss began an extremely quiet six-to-seven-year period for McManus, who then failed to qualify for any UK or World Championships between 2007 and 2013, and also struggled to qualify for the other ranking events (during the period between the 2006 Grand Prix and the 2013 Welsh Open, he failed to qualify for the main stages of 42 ranking events). This loss of form saw him quickly drop out of the top 16, then out of the top 32. His poor form reached a trough in the 2009/2010 season, where he failed to qualify for any of the main stages of the tournaments he took part in.