Ashleigh Barty described turning down Andy Murray's Wimbledon offer as her hardest decision.

Murray revealed on Thursday that French Open champion Barty was one of the players he had approached about playing mixed doubles at Wimbledon but she rejected the opportunity.

Barty is a contender for the singles title having lifted her maiden grand slam at the French Open and is playing in the women's doubles, where she is also a major winner, with Victoria Azarenka.

After beating Venus Williams 6-4 6-3 to reach the semi-finals of the Nature Valley Classic in Birmingham, Barty said: "When Andy texted me asking me to play, I was a little bit shocked, to be honest.

"Obviously I would have loved to have grabbed the opportunity to play with Andy, and I think it was the hardest decision I have ever had to make as to whether I'm playing an event or not.

"I took some time to think about it, and playing three events is just a little bit too much. When a champion asks you to play at any stage, I was very flattered and honoured, and I said to him, 'I think there are some pretty good options out there for you'. I'm sure he'll find someone.

"It was nice to see him playing yesterday. You can see how much he missed it, how much he loves it. I think the whole world was watching. I don't think there was a person in the tennis world around the planet that wasn't happy to see him out there again."

Barty is the form player in tennis at the moment having taken her new-found status in her stride and made a seamless transition from clay to grass.

She trailed Williams 4-1 in the opening set but won five games in a row and, having made it 10 victories in succession, is now only two wins away from overtaking Naomi Osaka as world number one.

Barty insisted she is not focusing on that, saying: "If world number one happens, it happens. If it doesn't, it doesn't. It's certainly not something I'm stressed about. If I keep putting myself in the right position and doing the right things, it may come, but if it doesn't, it's not the end of the world."

In the last four, Barty will take on Czech Barbora Strycova, who is something of a Birmingham specialist having reached this stage four times in the last six years and who defeated Kristyna Pliskova 6-2 6-4.

Strycova is among those to have put her name forward for the opportunity Barty rejected and, upon learning Murray would also be playing in Eastbourne, she said: "I'm going straight to him. We played some juniors together, so it would be really fun."

The other semi-final will pit eighth seed Julia Goerges, who knocked out Osaka's conqueror Yulia Putintseva 6-3 6-2, against unseeded Petra Martic.

The Croatian won a wild match against Jelena Ostapenko 6-7 (4) 7-5 6-1. After Ostapenko won the first four games, Martic hit back with five in a row but it was the Latvian who took the tie-break.

Ostapenko was then up 4-0 and 5-2 in the second set, holding five match points, but Martic saved all of them and the disappointment of that, along with a staggering 20 double faults, contributed to a poor third set from Ostapenko.

Martic said: "I still can't believe that I won this match."