Australian wildcard Thanasi Kokkinakis vented his frustration Thursday at being forced to withdraw from a second-round US Open clash with three-time champion Rafael Nadal due to injury.

Kokkinakis, the world number 203, won his first Grand Slam match since the 2015 French Open against Ilya Ivashka in the first round at Flushing Meadows but a right shoulder problem prevented him from facing Nadal.

“Cannot describe how angry and frustrated I am right now,” Kokkinakis tweeted.

“Having to pull out tonight after working so hard to get back to this point I’m going to figure it out at some point and it will all be worth it... Thank you to everyone who still supports me through the s***.”

Kokkinakis, 23, reached a career high of 69th in 2015 but his progress has stalled due to a series of injuries in recent years.

Despite that, he famously defeated Roger Federer in the second round of the Miami Masters in 2018.

He was making his third appearance in the main draw at the US Open, having lost in the first round in 2015 and 2017.