Mark Petchey has said he weclomes the "challenge" of coachign Emma Raducanu but admitted she has work to do.

"When she asked me to help in Miami, I was aware of the things that I wanted to change and see whether it helped her," he told TNT Sports.

"Serve was something that she wasn't feeling that comfortable with, which is what we worked on a new motion in LA.

"I like the challenge for her, because, in the last few weeks, she's played some really good players and some big ball hitters, and I think that's been important to her.

"Emma at this stage of her career despite what she's already achieved has some work ahead of her to be the best player that she can be."