Double fault! McIlroy takes his eye off the (golf) ball

Rory McIlroy may want to get his mind off the court and back on the course. After incurring a careless two-stroke penalty in the second round at the Abu Dhabi HSBC Championship that dropped him out of a share of the lead and into a tie with Tiger Woods for fourth at 5-under, the reigning U.S. Open champ tweeted that his concentration may have been elsewhere.

 "Apparently I missed an unbelievable tennis match today! Was busy making birdies, bogeys and others!!" @McIlroyRory tweeted Friday. "Need to limit mistakes at the weekend!"

Rory McIlroy has become a huge tennis fan since hooking up with Caroline Wozniacki (Photo: Julian Finney/Getty Images)

With his girlfriend, tennis star Caroline Wozniacki, losing her quarterfinal match -- along with her No. 1 status -- to Kim Clijsters in this week's Australian Open, McIlroy must have been referring to Novak Djokovic's five-set win over Andy Murray in the semifinal match of the men's Open. McIlroy and Murray became pals after the two met at Wimbledon last year.

McIlroy and Woods were only two shots back of leader Thorbjorm Olesen heading into the third round, but McIlroy's focus may still be Down Under, as his tennis buddy Roger Federer has a date with Djokovic in the final.

As for his on-course woes, Rory Mac made a rookie error when he brushed away some sand that was between his ball, which was some six feet off the green, and the cup on the par-4 ninth hole at Abu Dhabi Golf Course. Had his ball been on the putting surface, he would have been fine and McIlroy recognized his error as soon as playing partner Luke Donald called it on him.

"I just brushed the sand and Luke was like, 'I don't think you can brush sand off the fringe,'" McIlroy told reporters after his blunder. "And I'm like, 'Oh, yeah, you're right.' Just one of those things."