Johannesburg: Defending champion Charl Schwartzel missed the cut at the weather-hit Joburg Open on Saturday after struggling on the greens at the Royal Johannesburg and Kensington Golf Club.

England's Robert Rock and Richard Finch and South African George Coetzee share the lead on 11-under after two rounds of the European and Sunshine Tour co-sanctioned event.

The cut was set at 139 and Schwartzel missed out by a shot after rounds of 72 and 68 to finish on three-under-par in the tournament being played on the par-72 East Course and par-71 West Course.

"It's always guesswork when you come off a break and competitive golf is always different," he said. "But to get straight on to the point, my putting let me down. You're not going to be doing very well on a course where you should be going for birdies if you have 34 putts.

"I hit 17 greens in regulation but I was just three-under, so it was not my best effort," Schwartzel added.

"I'm not stroking the ball properly and I don't have that rhythm you get from playing tournament golf week in, week out.

"If you hit a few off-line, you start doubting yourself, which makes it worse," Schwartzel told reporters.