Tim Henman believes it is more important for Emma Raducanu to improve her physicality rather than settle on a new coach if she is to climb up the tennis world rankings.
The British No 1 is in action at this week's WTA event in Indian Wells, where a good run in California could see her rise from her current position of 24th in the world.
Raducanu, 23, has become notorious for regularly changing coaches since stunning the tennis world by coming through qualifying to win the 2021 US Open.
Last month, she said that she was in no hurry to find a new coach after Francisco Roig became the latest to leave the role.
Roig spent six months working with Raducanu, who went into the Australian Open not fully prepared because of a foot injury.
A see-saw start to the season has seen Raducanu reach her first senior final since the US Open, in Romania, and then struggle with illness – a common occurrence during her professional career.
Britain's former world No 4 Henman believes that greater strength and speed is the key to Raducanu's development.
"She has to become physically more resilient to be stronger and faster to then compete with the biggest hitters and the best players," he said.
Henman, who will be commentating at Indian Wells for Sky Sports, added: "You look at the physicality of a (Aryna) Sabalenka, a (Iga) Swiatek, a Coco Gauff, a (Elena) Rybakina, Emma's not at that level. And to a certain extent, with her physique, she might not ever be at that level, but she's got to close the gap."
Raducanu's split with Roig followed a second-round Australian Open defeat by Anastasia Potapova that saw Raducanu voice her unhappiness with the way she was playing under the Spaniard.
She will be aided at Indian Wells by British former player Mark Petchey, who served as a temporary coach for several months last season in between his broadcasting commitments, while hitting partner Alexis Canter provides daily support.
"I worked with three coaches in 15 years. I liked consistency and continuity, but that's not what Emma does," said Henman.
"I wonder whether in some respects she's better off without a coach and accepts the responsibility and just plays.
"I don't know what she'll do next and she probably doesn't either."