Vassell won't return to Wednesday's game against the Hawks due to a right quadriceps contusion, Paul Garcia of ProjectSpurs.com reports.
Vassell played 22 minutes and had three points (1-6 FG, 1-4 3Pt), three rebounds, two assists and two steals before suffering the injury. The severity of the injury remains unclear, and the 21-year-old should be considered questionable for Friday's matchup with the Celtics.