Andy Murray says it was "stupid" to think he could win Australian Open

Britain's Andy Murray said it would have been "stupid" to think he could win the Australian Open so soon after back surgery.

The Wimbledon champion lost 6-3 6-4 6-7 (6-8) 6-3 to Roger Federer in the quarter-finals at Melbourne Park.

It was Murray's second tournament since he underwent surgery in September.

"I wasn't expecting to come in and win the event; that would have been completely stupid to think that," he told BBC Sport.

"It's a very tough thing to do playing against Roger at that level, and even if I'd won I would have had to play Rafa [Nadal] in a couple of days.

"I'm happy to be playing at a good level just now and, with a few more matches and a bit of training and working on a few things, I'll hopefully be back to my best at some stage this year."

Murray arrived in Melbourne having played just two competitive matches in 2014 following a lengthy recovery process.

"I've come a long way in four months," the Scot said. "Obviously right now I'm very disappointed.

"There's a few things I would have liked to have done differently if I was ever to have surgery again, possibly.

"But it's the first time I have ever gone through something like that. I thought I did a good job getting myself in good shape to be competitive at this level.

"I wasn't too far away in the end. With a few things that you can tweak here and there, maybe I could have found a few extra per cent."

Murray, 26, is a three-time finalist in Melbourne and had been trying to make the semi-finals for a fifth successive year.

"It's frustrating because it's basically been four months when I've been lying on my back not being able to move or walk," he said.

"A lot of work went into this Slam compared with other ones where you have a few weeks to prepare. This time I had a long time to prepare, maybe just not enough matches."

Federer, 32, was in terrific form for much of the quarter-final, dominating on serve for the first two sets as Murray struggled to get a foothold in the match.

"I didn't return well enough in the first two sets," said Murray. "He served extremely well. As much as I would have liked to have returned better, he served very well and didn't allow me to do that.

"When I had the opportunities, some second serve returns and stuff, maybe I didn't make him play enough.

"There's a few points here and there where I hit tapes on returns and missed the shot by a little bit. But he started off the match playing great, great tennis.

"I'm glad I managed to respond and made the match competitive."

Murray is next scheduled to play in Great Britain's Davis Cup tie against the United States in San Diego later this month, although he is not relishing a switch to clay.

"It's not perfect for rehabbing after back surgery," he said. "Ideally I'd stay on the same surface."