Andy Murray admits his Australian Open preparations are being affected by the upcoming birth of his first child.
Murray has made it clear he will cut short his first Grand Slam of the year and fly home if the baby arrives earlier than its expected due date in mid-February.
Gunning for a third major title, Murray is a serious contender in Melbourne but says he is currently struggling to keep focus all of the time.
"Most days I think about the baby," Murray said. "Just now it's a big change coming. It's very, very exciting. I'm sure everyone that's had their first child in here would have thought the same thing with just a few weeks to go.
"I've never been in this position so it's something new for me to deal with and handle, which is good.
"New experiences are always good, something to learn from, but when I'm on the practice court and stuff, I'm very focused there. When I've been training, I'm not distracted on that side of things.
"Just obviously after your practices and when you're away from the court, it's a bit different."
Murray is yet to win the Australian Open despite reaching four finals in the last six years, three of which he lost to Novak Djokovic.
If the pair meet again at the last stage and the most dramatic scenario materialises of his wife Kim going into labour, Murray confirmed he would still quit the tournament even with one match left to play.
"The same thing would happen," Murray said. "For me, my child is more important to me, and my wife is more important to me than a tennis match."
Before then, Murray must overcome 18-year-old German Alexander Zverev, whom he faces in the first round on Tuesday.
Zverev, measuring 6-foot-6 and ranked 83rd in the world, is one of the game's most exciting young talents and proved his worth last year by beating world No.12 Kevin Anderson, Murray's conqueror at the US Open.
The British No.1 has never encountered the teenager before in a professional match but, by chance, played him last week at the Hopman Cup in Perth, where he won comfortably 6-3, 6-4.
"I know him reasonably well," Murray said. "I practised with him for the first time a couple of years ago. I've seen him play a few matches since then.
"Getting to play him a couple of weeks ago was good. I also practised with him a couple of times during the week in Perth too.
"He's a big guy for his age. Of the young guys coming through, he is by far the tallest of them, which has obvious benefits.
"At the age he's at just now he can cause a few issues. He's still filling out his physique but he's got a very good game.
"He serves well. For a big guy, he moves pretty well, too. He's improving all the time. It will be a tough match."