Option 1: Buy 3~5 bench players to use up those 15ish minutes.
Option 2: Place your players out of natural positions. For example, put PG into C position, SG into PF position, place SF into PG spot, put C into SF position, and put PF into SG position. The aim is to let them foul out in 30ish minutes. Sadly, your SG/SF would probably play 48 minutes as both could play numerous roles in the lineup.