Roberto Bautista Agut is in the midst of his best run at a grand slam, reaching the Australian Open quarterfinals.

But, it could have been so much different had the world number 24 and nine-time ATP Tour winner from sunny Spain pursued his other love – football.

Born in Castellon de la Plana in the east of the Iberian Peninsula, Bautista Agut impressed with his football skills for hometown club CD Castellon, who boast past players such as Vicente del Bosque and Gaizka Mendieta.

Bautista Agut caught the attention of LaLiga side Villarreal and it is there where the Spaniard played until the age of 14, before turning to tennis.

"When I was a kid I went to Madrigal Stadium to watch Villarreal, I dreamed of becoming a footballer," Bautista Agut told LaLiga via Twitter in 2017.

"Until juniors, I was playing at Villarreal. I played the Brunete tournament. I was less technical, but I was scoring goals even with my ears."

Bautista Agut added: "I would have liked to play football well but could not do both things…  I left the football shoes and I took the racquet forever."

Now, Bautista Agut is enjoying one of his best runs on the ATP circuit.

Buoyed by his upset over Novak Djokovic en route to glory in Doha earlier this month, Bautista Agut was the villain when he potentially sent three-time slam champion Andy Murray into retirement at Melbourne Park on day one.

He then upstaged 10th seed Karen Khachanov before outlasting 2018 Australian Open runner-up Marin Cilic in five sets for a spot in the last eight of a slam after 25 main-draw attempts and nine prior fourth-round losses.

"I've been playing very good tennis. I won really good matches," Bautista Agut told reporters following his 6-7 (6-8) 6-3 6-2 4-6 6-4 victory against Cilic. "I had to fight so hard to stay very focused. It's been a great month for me and for my tennis."

As the 30-year-old prepares for a mouth-watering clash with Greek sensation Stefanos Tsitsipas, Bautista Agut's decision to drop football for tennis appears to be the right one.