[Mark T. DeNucci, Sr.]

From the FIBA Rules Book:

4.2 Rule
4.2.1 Each team shall consist of:
• No more than twelve (12) team members entitled to play, including a captain.
• A coach and, if a team wishes, an assistant coach.
• A maximum of five (5) team followers who may sit on the team bench and have special responsibilities, e.g. manager, doctor, physiotherapist, statistician, interpreter, etc.
4.2.2 Five (5) players from each team shall be on the playing court during playing time and may be substituted.
4.2.3 A substitute becomes a player and a player becomes a substitute when:
• The official beckons the substitute to enter the playing court.
• During a time-out or an interval of play, a substitute requests the substitution to the scorer.

It is my reading of FIBA R4.2.2 that the Team in the OP must play with five players if it has five eligible players.

MTD, Sr.