Andy Murray is no longer in pain but remains unsure whether he will be able to play top-level tennis again.

The former world number one had his second hip operation five weeks ago as he bids to overcome a problem that first became a serious issue in the summer of 2017.

Speaking at Queen's Club while announcing a long-term partnership with British clothing brand Castore, Murray said: "I want to continue playing, I said that in Australia. The issue is I don't know whether it's possible."

Murray laid bare his struggles at a tearful press conference ahead of the Australian Open, announcing he was planning to retire after this summer's Wimbledon but that the Melbourne tournament may be the last of his career.

That may yet turn out to be the case but Murray will attempt to break new ground by returning to top-level singles action.

He said: "I'm a lot happier now than I was, certainly the last 12 months, because I have no pain in my hip now and I was in pain for a long time.

"The rehab is slow but it's been going pretty well. I just need to wait and see how things progress. If it's possible, I'd certainly love to compete again."

Castore was set up by brothers Phil and Tom Beahon in 2015 and Murray first wore the clothes on a match court in his dramatic five-set loss to Roberto Bautista Agut in the first round in Australia.

While a long-term partnership would indicate Murray is hoping to play for several more years, the Scot is also thinking ahead.

He will become a shareholder in the company and help with product development as Castore looks to establish itself in the tennis market.

Murray, who has invested in a number of British start-ups, said: "It's high-quality clothes and the fact it's a young British company, it's two brothers who have played sport, there's synergy there obviously with my story.

"Normally the brand-athlete partnerships are you get paid to wear the clothes on court and take some photos, then at the end of that contract there's a negotiation. Whereas with this it was quite different. Obviously I'll have some equity in the business.

"It's something that, even when I've finished playing, I'm going to have a big involvement in as well and, as I start to get a bit older, you start to realise there's other things that you have to look for and different interests, and this is something that was really exciting for me."