A shocking coaching change, off-court distractions, the pressure of added expectations as world No. 1: There¡¯s no one-size-fits-all explanation for Naomi Osaka¡¯s struggles since winning the Australian Open.

All three were among the reasons American tennis legends and commentators Chris Evert and John McEnroe cited last week in a conference call with reporters in the lead-up to Wimbledon, which starts Monday.

Osaka has gone 13-6 since winning her second consecutive slam and her surprise announcement shortly afterward that she had split with coach Sascha Bajin. She¡¯s yet to play in a tournament final since, only making it as far as the semifinals once in eight tries. After multiple close calls, she finally lost her No. 1 ranking to Ash Barty last week.