Final answer:
In summary, a player receiving a yellow card may need to sit out if playing indoor or modified soccer. Being scored upon during this penalty doesn't change his penalty time, which must be completed. A subsequent blue card usually results in a harsher penalty, potentially extending the sit-out time or leading to an ejection.
Step-by-step explanation:
If a soccer player receives a yellow card and has to sit out for three minutes, there are specific consequences for his team if they are scored upon during his absence. Usually in soccer, a player receiving a yellow card does not have to leave the field. However, considering the case of indoor or modified soccer rules where they do sit out, the team will continue playing with a player short. If the opposing team scores during this time, the penalized team continues to play short until the penalty time is complete unless the rules of the competition specify that the penalized team can return to full strength immediately after a goal is scored against them.
If that same player then receives a blue card for dissent while on the bench, this typically indicates a more severe penalty often seen in indoor soccer leagues such as accumulated fouls or serious infractions. The exact consequences would depend on the specific rules of the league, but it could lead to an additional time penalty or even an ejection from the game, with further sanctions to follow depending on the league's disciplinary system.