MELBOURNE, Feb 9 (Reuters) - Quotes from day two of the Australian Open tennis championships on Tuesday:
* "Nick likes to say things. Some of them can be true, some cross the line. I think he has a brain in his head when he says stuff. There are many stupid things that he did in the past but there are things he has said in interviews ... that could be considered true." Stefanos Tsitsipas on Nick Kyrgios' war of words with Novak Djokovic.
* "I pulled my ab and that made it difficult for me to serve and that is why I had to retire. I feel like I am in a bit of shock so I don't fully know yet anything. I haven't yet been able to check in with the physios." Johanna Konta on why she retired from her first-round match.
* "I have doubles. I'm probably in good enough shape to play half court decently well. That being said, if it's hot and humid, maybe not." Tennys Sandgren on on his plans after his singles exit.
* "My back is not perfect. Every day that I'm able to go through, probably there are more chances to get better. Today it's not great. I needed to change a little bit the motion of my serve. That's what I tried to survive today." Rafa Nadal on his back injury.
* "We went mini-golfing at Holey Moley, which is pretty fun. It's probably my favourite mini-golfing spot in the world. My whole team went, and I came in last twice. We're going again today to get a rematch, and my goal is to not come in last." Coco Gauff on how she is spending her time away from the courts.
* "The most creative way possible is hitting against the wall and soft cushions. Doesn't work. But I think the biggest impact for me personally has been not being able to have fresh air. That really took a toll." Victoria Azarenka on preparing for a Grand Slam while in quarantine.
* "I wanted the fans to interact and help me choose what I should wear because I think it's a pretty important topic for a women's tennis player. They voted for the white and gold, so I kind of married these two." Belinda Bencic on running a social media poll asking fans to help her choose her outfit.
* "Obviously she's playing the defending champion, so of course she's more loose. I obviously am tight. I wasn't there 100% mentally. But a win is a win and I'll take it." Sofia Kenin on her victory over local wildcard Maddison Inglis to open her title defence.
* "I try to be focus on me, not on social media. I try (not) to be a part of the social media and don't hear the comparison with Rafa. I try to do this." Teenager Carlos Alcaraz on comparisons with fellow Spaniard Rafa Nadal after winning his first Grand Slam main draw match.
* "I feel it's an issue of maturity. Tennis players never relax, no matter which round, which tournament. I feel like now I approach it differently. I accept the fact that it can go wrong. I'm more open to adaptation, to uncertainty." Former French Open and Wimbledon champion Garbine Muguruza on how her outlook has changed as she has grown older.
Day two highlights