As first reported by GolfWeek, Clark, a South African, has encountered visa issues that seem set to leave him out of next week's field.
Clark is subject to his home country's travel laws as well as those of the United Kingdom, which have become more strict in recent years for South Africans. In the event he wants to apply for a visa, he has to plan weeks in advance.
"That's the hardest place to go is the U.K.," Clark told GolfChannel.com on Wednesday following his pro-am round at the John Deere Classic. "Most places I need a visa, but they make it extremely difficult and I don't know why.
U.K. laws concerning South Africans applying for visas were tightened in 2009. The process now involves a biometric screening that includes finger-printing. To get that far, Clark first needs a statement of purpose for his visit which he says the R&A wouldn't grant him until he officially qualified.
"The disappointing thing for me is that I tried to start this process six weeks ago and [the R&A] wouldn't send me a letter," Clark said. "I've emailed back and forth with them and told them, 'I'm stuck right now. I can't come unless there's something you can do right now.' I even contacted the Tour to see if there was something they could do, because in my mind there has to be a way where they can get something expressed or a waiver or something, but nothing has come about. So I just can't go."
Clark, last year's Canadian Open champion, said he didn't start the process any sooner because he was outside the Official World Golf Ranking's top-50 cut-off to qualify in May, and because he's been battling elbow issues all year. Clark returned to the PGA Tour two weeks ago at the Travelers following surgery, playing his first event since the Sony Open in January.
"[The Open] wasn't even on my radar," he said. "About six weeks ago, it looked like I was going to get in, so I set about trying to get my visa. ... I know [the R&A's] excuse was that the British embassy wouldn't let them send a letter, but that doesn't help me."
Clark also said he was on vacation when he was informed of his invite and couldn't send his passport as part of the screening process because he needed it to travel.
Asked if he's encountered any other South Africans with similar issues, he responded that the other qualifiers either earned their invites sooner - granting them more time - or play the European Tour regularly, so they have their documents in order.
This week's John Deere is part of the Open Qualifying Series, which could provide an extra invite to a player who finishes inside the top five and isn't already invited to the year's third major.
"What if I had come here and qualified? There would have been zero chance [of getting a visa]," he said. "And I'm playing a tournament this week. I can't be flying off for New York or wherever [for finger-printing]."
"I kind of wish the R&A would have been a bit more forthcoming," he added. "I also thought the Tour could have pulled a few more strings and got them to jump into gear, but I guess it's not their concern."