Padraig Harrington’s hope of qualifying for next month’s WGC – Cadillac Championship took a back seat on day three of the Northern Trust Open in suburban Los Angeles.

A week after finishing in a share of seventh at Pebble Beach, Harrington posted six bogeys and just one birdie in a third round 74 to crash down the board and into a share of 66th place at five over par on the Riviera Course.

Harrington will go into the final round a dozen shots behind the leading pair of Phil Mickelson and Keegan Bradley.

It’s the second straight year Harrington has put together two solid opening rounds but only to undo his good work on day three.

In 2011, the triple Major winner record a 68 and 71 but then fired a 75 that is his highest score in 18 rounds of the former 1995 U.S. PGA Championship host venue.

This year, Harrington posted a first round 74 but then moved well up the board with a round two of 70.

Harrington, currently ranked 86th in the world, has already failed to qualify for next week’s WGC – Accenture Match-Play Championship and has until March 5th, 2012 to get himself back inside the top-50 if he’s to tee up on the Blue Monster course at Doral.

It will mean Harrington having to capture next fortnight’s Honda Classic, as he did in winning his first PGA Tour event in 2005, to be assured of competing in the seasons second $US 8.5m WGC event.