Nov 9 (Reuters) - Defending champion Carlos Ortiz has pulled out of this week"s Houston Open with a left shoulder injury, the PGA Tour said on Tuesday. Ortiz, fresh off a runner-up finish last week in his home country of Mexico, is dealing with the same shoulder issue that forced him to withdraw midway through the Zozo Championship last month in Japan. "Unfortunately, I"ve been battling a left shoulder injury since Japan and after meeting with my doctors this morning, it was recommended that I take the rest of the season off to recover," said world number 49 Ortiz. "This is incredibly disappointing to me as I was looking forward to defending my first PGA Tour title in Texas, my second home. I’m honored to be a champion of this event and I look forward to returning next year." Ortiz carded a five-under-par 65 in the final round last year in Houston to hold off Dustin Johnson and Hideki Matsuyama and become the first Mexican to win on the PGA Tour in 42 years.