PERTH, Australia -- Bringing ATP and WTA stars together at the United Cup may be something new, but many of the cross-Tour friendships within the 16 competing teams have considerably longer histories.

Take Team Croatia’s Borna Coric and Donna Vekic, who have known each other so long they can barely recall their first meeting.

“I think it was almost 20 years ago, so I don’t remember a lot, but we’ve known each other basically since we started playing tennis,” WTA No.67 Vekic told this week in Perth. “We’ve been together for our whole career.”

Coric retains a few more memories of the pair’s early days in their homeland.

“I remember her, we were playing under-10s in Zagreb,” said the ATP No.26, before smiling and starting to tease his teammate about her younger self. “I didn’t like her much back then actually, back then she was very nervous, very arrogant as well, but now she changed. So, I’m just enjoying spending time here with her and the whole team.”

“I don’t remember being arrogant!” laughed Vekic in response. “We’ve been friends for a very long time, and I think it’s maybe the last couple of years that we are even closer than before. We’ve spent almost every week together on tour [over the years] so it’s good to have a close friend.”

That mutual support has helped Coric and Vekic each come through tough challenges in recent years, with both undergoing surgery within three months of each other in early 2021. Coric only returned to the ATP Tour in March 2022 after a year out due to his shoulder injury, while Vekic’s knee operation in February 2021 caused a three-and-a-half-month absence and a longer battle to recapture her pre-surgery form.

Those difficulties made subsequent successes in 2022 even more rewarding for the pair. Coric lifted his maiden ATP Masters 1000 title in spectacular fashion at August’s Western & Southern Open in Cincinnati, while Vekic took out Top 10 opponents Maria Sakkari and Aryna Sabalenka at the San Diego Open in October, before pushing World No.1 Iga Swiatek to three sets in the final.

“I’m just happy to see her do well,” said Coric. “She had a very, very tough year with the knee, and I had a very tough year with the shoulder, so obviously I’m super happy to see that she is doing well as well.”

“It’s great when we have success together, but we also went through a very difficult time in our careers, almost at the same time,” added Vekic, who was ranked No.29 at the time of her operation but has a career-high of No.19. “With my knee surgery, his shoulder surgery. It was great to have each other during that time, and now we are back together playing and that’s even more enjoyable.”

There were many highlights during Coric’s barnstorming run in Cincinnati, where he defeated five Top 20 players in a row, including Rafael Nadal, Felix Auger-Aliassime and Stefanos Tsitsipas en route to the title. Vekic was in the stands supporting her countryman during his second-round triumph against Nadal, although her abiding memory of the weather-affected match has little to do with Coric’s on-court exploits.

“I was super annoyed with that rain delay, I wanted to go back and sleep!” joked Vekic. “But it was a great victory for him, yeah.”

Those positive vibes appear to have carried over into the 2023 season, as Coric and Vekic prepare to spearhead Croatia’s United Cup bid alongside WTA No.38 Petra Martic. On Saturday, Vekic will meet Argentina’s Maria Carle while Coric takes on Francisco Cerundolo in their nation’s first tie in Group F.

“We feel great here,” said Vekic. “The atmosphere is amazing. I was in Perth once 10 years ago and I’m really happy to be back. Hopefully we can go through the group stage.”

The duo is also slated to team up in Sunday’s mixed-doubles rubber at RAC Arena, although Coric admitted that some hard work on the practice court is required to ensure their on-court combination is ready.

“We will go to the practice court right now and we need to play some doubles, because I haven’t played any doubles for a very long time,” he said. “I think it’s the same for her [Vekic] to be honest… Maybe we played doubles [together] a couple of times, when we were 16 or 17, but we didn’t play together for a very long time, so it’s going to be very interesting if we go on the court and need to play.”

Should Coric and Vekic partner in Sunday’s doubles clash they will certainly hope their respective games are more in sync than their sense of fashion. The pair recently exchanged light-hearted shots on the topic on Twitter.

“I’m in a safe zone this week,” said Coric, referring to the standardised Team Croatia kit. “I cannot miss, so she cannot say any bad things.”

“I can still make fun of his hair!” retorted a laughing Vekic, a possibility Coric appeared to have already prepared for.

“That’s why I will [keep] my hat on!” he said.