After an opening-round 76, he was 5-over through nine holes on Friday.
Clark, who won the Canadian Open last month, has struggled with an elbow injury in the past. Three years ago, an injury to his right elbow forced him to miss almost the entire season.
It took him most of the next year to feel close to normal again.
“Literally I felt it the Monday after the Hawaii tournament,” he recalled recently. “I finished second in Hawaii. Everything was great. Got home, woke up the next morning, and I couldn't move my arm. Whether it was something that happened traveling with bags, or something that I might have done during the round on that Sunday, I'm not sure, but unfortunately for three or four months I tried to rehab it to get it better. Surgery's normally the last thing you want to do.
“After four months of not getting better, I eventually had surgery. That took another four months of recovery, four or five months.
“Then I came out and played in 2012, but it takes a while to get your game back. Not only physically, but the mental side of it.”