During a 2015 match against Svetlana Kuznetsova, Venus Williams employed a few dogs as four-legged ball boys. At the time, it was seen as an adorable novelty, little more than a one-time stunt pulled during a friendly tennis match. But it seems like hiring canine ball boys may be catching on. Last week, Gastao Elias and Roberto Carballes Baena hired four rescue dogs to retrieve tennis balls during a match at the Brazil Open.

According to Time, the dogs—named Frida, Mel, Isabelle, and Costela—were all strays, rescued from the streets of Sao Paolo and trained to chase down balls during tennis matches. During the game, the four dogs, clad in orange bandanas, retrieved tennis balls with guidance from trainer Andrea Beckert.

"We want to show that abandoned dogs can be adopted and trained," Beckert told CNN. "After all, it's not easy to get a dog to only pick up the lost balls, and then to give them up!"

Beckert works with the Association Of Animal Wellbeing and hopes the Brazil Open will help raise awareness for her organization. Check out the dogs in action above.

[h/t Time]

Banner Image Credit: ATPWorld Tour, YouTube