Injury concerns as Rory McIlroy admits "tweak" in his back during South African Open

The world number two was on fire today as he carded a second round 68

Rory McIlroy

Image: Kamran Jebreili AP/Press Association Images

Rory McIlroy was able to finish his second round before play was called off for the day due to threat of lightning, but the world number two was on hand to provide all the day's spark.

A second round 68, including an incredible run around the turn, showed signs that the 28-year-old is thriving equipped with new clubs but drew concern after his round after admitting he had hurt his back.

"I thought about pulling out before teeing off today," he told the European Tour's official Twitter account. "I tweaked my back somehow & the first few shots today weren’t very comfortable."

With the second round set to resume tomorrow, McIlroy will be afforded additional time to rest up before he gets back out on the golf course.

He started his day rather inconsistently, a bogey on the first was followed by a birdie and then the Holywood native dropped two shots on the third.

Three consecutive pars preceded an incredible run of -8 through holes eight to 15, picking up six birdies, one par and an eagle. Of those birdies, four stretched from holes 12 to 15.

While his first drive of the day travelled 392 yards, it was all about his putter this afternoon with eight consecutive one putts around the turn.

Two bogeys on his final two holes saw him concede a share of second place and drop back to fifth for the tournament.

Much was made of his club selection before the start of 2017 after Nike discontinued their line of golf clubs. This allowed McIlroy to experiment with different suppliers, something which appears to have paid dividends.

Concerns will remain as to the extent of his back injury and whether it will force him out of the competition.