Raducanu continues to be without a full-time coach after she ended a short-lived trial with Slovakian Vladimir Platenik earlier this week.

Against Navarro, she had Mark Petchey - a well-known figure in British tennis circles who worked with her as a teenager - offering coaching advice from her box.

Raducanu's representatives described Petchey as a "familiar face" who was providing "support".

It is not clear, though, how long the arrangement will go on for.

Petchey, 54, also coached Andy Murray in the early part of the three-time major champion's professional career, before becoming a prominent television commentator and analyst.

He watched the match against Navarro alongside Raducanu's team, which consists of long-time ally Jane O'Donoghue and fitness trainer Yutaka Nakamura in Florida.

"I came here with someone and it didn't work out, but we put in some great work," said Raducanu, who plays 48th-ranked American McCartney Kessler in the last 32.

"I have good friends here with me, who know my game and know me so well - it's about trusting your gut and trusting your feeling.

"I think that's how I got through to be honest."