I think any ST holder can go Monday - just book a ticket they are on general sale to ST holders.
Those who didn't win the Chelsea ballot had first dibs on the Youth game but it's now been opened up to all ST holders from today.
Some people who didn't get in the first Chelsea ballot were offered a second bite of the cherry for the Chelsea game today - so some of us who already had a ticket for Monday managed to snag a ticket for Sunday too. But there's no reason it wouldn't work the other way round too.