MELBOURNE, Australia -- Blame Roger Federer. After all, it was Federer who made us believe that anything was possible for Novak Djokovic at this year's Australian Open. A year ago, the Swiss, then 35, won the event after taking six months off with knee and back injuries.

Djokovic came into the 2018 Aussie Open fresh off an absence that shelved him for half a year as well. But after an encouraging start to the event, Djokovic fell to Hyeon Chung 7-6 (7-4), 7-5, 7-6 (7-3) in the fourth round Monday, citing an elbow injury afterward. In other words, a bad day for the 12-time major winner became that much worse.

There is also the possibility that Djokovic will face a nightmare scenario of more time away from the game if he doesn't feel an immediate improvement.

His loss to Chung, whose unbelievable court coverage reminded those watching of Djokovic himself, wasn't fully unexpected. Djokovic didn't play too badly against an inspired opponent. The winner of the Next Gen Finals in Milan last year, the 21-year-old Chung has showed he is ready for the big stage. But at the end of the day, this match was about Djokovic and his health woes.

"It's not great," Djokovic said of his elbow. "At the end of the first set, it started hurting more. ... I had to deal with it until the end of the match. It's frustrating, of course, when you have that much time and you don't heal properly. But it is what it is.

"There is some kind of a reason behind all of this. I have to reassess everything with my team, medical team, coaches and everybody, scan it, see what the situation is like. Last couple weeks I played a lot of tennis. Let's see what's happening inside."

There were plenty of people who believed Djokovic, a six-time champion Down Under, could win another title here this year. But the truth is, that always seemed unlikely. He hadn't even played a competitive match this season before arriving at Melbourne Park, and came into the year's first major with a new, abbreviated service motion.

When Djokovic pulled out of the Qatar Open at the start of this month with his injured elbow, there were rumors he might decide to bail on the Australian Open as well. That he wanted to play in Melbourne is a testament to his competitive spirit and his desire to return to the tour as soon as possible. But perhaps his aspirations were a little too shortsighted.

Monday's loss to Hyeon Chung marked Novak Djokovic's first straight-sets defeat at the Australian Open since 2007. Cameron Spencer/Getty Images

On Monday, Djokovic was not in vintage form, even if his movement looked good. He didn't play badly, battling back from 4-0 down in the first set and 5-3 in the second to make it close.

But his serve lacked consistency. The fact that he had issues with the motion is one thing, but it's disconcerting that all the work he did to manipulate the motion for the sake of his health did not seem to work.

Djokovic is a more aggressive player than most people give him credit for, but he is not in the same mold as Federer, whose serve gives him numerous free points and whose comfort at the net means he can shorten points relatively easily. Djokovic has to work harder for his points, which means his body takes more wear and tear.

The former world No. 1 says he is grateful he was able to play four matches when he wasn't sure whether he'd be here at all. But there isn't much fun in losing. And even less fun when that loss is coupled with pain.