[Kevin Sevcik]

According to <G10>:

ROBOT Starting Positions – Prior to the MATCH, each TEAM negotiates within their ALLIANCE to select one of the three LAUNCH PADS of the ALLIANCE. Each ROBOT is then HITCHED to the TRAILER assigned to the selected LAUNCH PAD. The ROBOT and TRAILER are then placed entirely within the LAUNCH PAD, and positioned such that the TRAILER is in contact with the AIRLOCK or guard rail (as appropriate).

TRAILERS are assigned to LAUNCH PADS. So I assume they're always on the field, whether there's a robot or not. A robotless TRAILER is going to be a dead easy target to score on, so I think a 2 robot team is going to have a huge detriment. So.... Don't forget to show up for a match!