Keep outdoor tennis open during lockdown 2 for singles and household bubbles

There is no logic to ban playing of tennis when playing within a household at all and the physical and mental benefit is huge - especially given it’s an outdoor activity.
Further, singles should be allowed with distancing because the broader rules allow taking of exercise with one other in a public setting. If transmission via tennis balls is a concern, players can simply serve using their own balls and not touch the other players balls as we did before.