RUSSELL KNOX prided himself on being comfortable in the uncomfortable conditions on day two of the rain-interrupted Honda Classic at Palm Beach Gardens, Florida.

Knox, despite three separate stoppages amount to a three-and-three-quarter hours delay, showed his true mettle in carving out a two under par 68 for a three under par PGA National clubhouse tally in the $US 6.1m event.

It put the 29-year old in the clubhouse in third place and three adrift of American Patrick Reed (67) who leads at six under par while behind England's Luke Donald (67) is at four under par.

World No. 1 Rory McIlroy let his honesty shine through yet again admitting he was 'pissed off' in missing the expected three over par cut with scores of 73 and 74 for a seven over par tally, and on a course he won in 2012 and was joint runner-up with Knox a year ago.

It is the first time since last year's Irish Open McIlroy has missed a cut while it's the first occasion since he walked off after 26 holes of the 2013 Honda Classic McIlroy has not played all four rounds in a regular PGA Tour event.

Knox clearly drew on his experience growing up in Inverness recording three birdies, including a 153-yard 8-iron gem to just two feet at the second, and just one bogey from a greenside bunker at the fourth, to be again in contention for victory.

"One of the things I love about this golf course is that you're never comfortable as every hole is so 67)demanding and it helps keep your focus," said Knox.

"I feel one of my strengths is being comfortable in the uncomfortable and in saying that I would consider myself a grinder giving I grew up in Scotland in constant tough conditions where all you really can do is chip and putt to make your sure.

"So I have always considered myself having the ability to get the ball in the hole as quick as possible and today I needed every bit of having grown up playing golf in Scotland.

"And as tough as this golf course in going to play in the two days we've had so far, so I am just happy I survived."

Knox had been at the course since 5.30am local time in readiness for a 7.05am tee off and with the delays, it was not to around 3.30pm he completed his round with a par.

However if there is one aspect of Knox's game that is most pleasing is his putting having taken 28 putts on day one and two less in his second round.

"Over these two days it is my putting that has been most pleasing as this is the hardest I have been working on my putting on Monday, Tuesday and Wednesday ever, so it's paying off," he said.

"I am stroking the ball as good as I ever had and it's the same putter that got me into the play-off last year albeit for a new grip that is helping me roll it down the line good.

"And I've been working with Ted Galino from Seymour Putting because I needed to gain some more confidence in my putting.

"So it feels after the three days with Ted I have done a 180 as my putting is so much better than it was the past two weeks practicing at home."

Fellow Scot Stephen Gallacher was on the 16th hole and just one shot outside of playing all four rounds.