For Lowry to get into the allstar game, the stars have to align for him. He can't afford to miss any more games. The team has to go on a decent winning streak to get some attention from media and coaches. The rockets have to be top 5 team in the West in standings by the time decision is made.
To be honest, Im not sure... I guess the coaches will make any final adjustments or decisions. If you want an answer for that question it should be top 3 for each position.