Rune won the first two sets, but still lost after five sets against the world No. 143, Nicolas Jarry.
"I have had many hard defeats in my career; this is just another one."
"I feel that I am doing many right things to get ready for the tournaments", said Holger Rune after losing 6-4, 6-4, 5-7, 3-6, 4-6.
He lost a very close third set and then collapsed in the fourth set. Rune explains that the knee pain was the reason for the dip in performance.
"I started well and played well in two sets, and then lost the third set a bit unluckily. In the fourth set, I started to feel my knee and got treatment. I couldn't serve and hit my backhand like in the first two sets", explains Rune.
"It's a shame. With all due respect to Jarry, under normal circumstances, I would have beaten him nine times out of ten."
Rune said that it was an old knee injury, which also irritated him during Wimbledon last year and subsequently also bothered him in parts of the hard-court season, which prevented him from reaching the level he showed in the first two sets.
"I didn't expect it to come back. I don't know if it's worse or better this time, or if it's serious. I'll have it checked before I go back to the training ground, and then I'll take it from there."
In the fourth set, Rune seemed to be drained of energy, but he denies that there were other challenges than the knee.
"There was nothing wrong with my energy. I was definitely also satisfied with my physique and moved well and dynamically, and played solidly and efficiently in the first sets. Then he started to serve a lot better from the start of the third set", said the disappointed Dane.