Stefanos Tsitsipas spoke of "insecurity" in his game after his first round loss to Alex Michelsen in four sets at the Australian Open.

"It was a difficult first-round match," said Tsitsipas. "I knew I was dealing with a pretty serious opponent because I've played him before and I have lost.

"So I knew I had to be on top of my game to try and win this match. I had a very slow start to the match.

"In terms of finding my movements and just dominating from the serve plus one, it wasn't really the way I'm expecting it to work. That led to some frustration and, let's say, insecurity in terms of approaching my game."