Maybe, they meant this:
“When should face masks be worn?
Face masks have been shown to decrease transmission rates of SARS-CoV-2, including in the context of
indoor sports. Athletes should be encouraged to wear face masks at all times (ie, group training, competition, and on the sidelines)
during activities that pose a high risk of transmission, Individual sports performed outside, such as golf and singles tennis, are lower risk for transmission of SARS-CoV-2, and a face mask may not be necessary for these activities if the athletes are appropriately distanced. Face masks have been shown to be well tolerated by the majority of individuals who wear them for exercise, but we acknowledge that the mask may need to be removed under certain circumstances.
Face masks should not be worn for competitive cheerleading (tumbling/stunting/flying) and gymnastics (while on the different apparatuses) because of the theoretical risk that the mask may get caught on objects and become a choking hazard or accidently impair vision. During wrestling contact, a face mask could become a choking hazard and is discouraged unless an adult coach or official is closely monitoring for safety purposes. Individuals who swim/dive/participate in water sports should not wear a face mask while they are in the water, because a wet face mask may be more difficult to breathe through. Any face mask that becomes saturated with sweat should be changed immediately.
Athletes should always wear a face mask between practice drills, on the sidelines, arriving at or departing from the playing facility, in a locker room, while not on the playing field, and during shared transportation to/from an event. It is important that the face mask fits the athlete well and is worn over the nose and below the chin. If the face mask is removed for a break, the athlete should remain at least 6 feet away from all other individuals.
Face masksshould be worn by coaches, officials, spectators, and volunteers at all times. Coaches and other club/school officials should monitor proper use and encourage all athletes to have a properly worn face mask in place in accordance with the above guidance.
Indoor sports have a higher rate of transmission of SARS-CoV-2 when compared with outdoor, and certain sports (eg. ice hockey and wrestling) carry higher relative risk. The risks and benefits of
indoor sports, in addition to the current community prevalence of COVID-19, should be carefully considered when making decisions about continuing or resuming
indoor sports. Proper use of a face mask for all
indoor sports training and competition (except in the examples noted above) is strongly recommended, because it has been associated with a decreased risk of SARS-CoV-2 transmission, equivalent to outdoor sport transmission rates.
Special considerations may be appropriate when there is an increased risk of heat-related illness. Individuals younger than 2 years old should not wear a face mask. Younger athletes may find wearing a
face mask challenging and may need to be reminded and/or assisted by parents/coaches. People should be reminded not to touch the front of the face mask and remove it from the straps whenever possible. When using cloth face coverings, they should be routinely washed daily in hot water and not reused until cleaned.”
So, AAP says always for indoor sport, and whenever not on the field for outdoor. I think CDPH got it wrong, but we should follow the rules so we don’t risk losing fields.