Background: Effective playing time (EPT) is a crucial determinant of the physical, technical, and cognitive development of young soccer players. Reducing match interruptions may enhance game rhythm and support player progression. This study examined the effects of a rapid-restart protocol, based on the availability of spare balls (SB), on EPT, sprint performance, and agility in young Tunisian players. Methods: Sixty male youth players (aged 11–16) from a Tunisian first-division club were randomly assigned to an experimental group (EG, n = 30) or a control group (CG, n = 30) across three age categories (U12, U14, U16). The EG played 10 weekly matches using the rapid-restart protocol, while the CG competed under standard conditions. Sprint performance (5 m, 10 m, 20 m) and agility (Illinois Agility Test, IAT) were assessed at baseline (T0), mid-intervention (T1), and post-intervention (T2). EPT was determined through video analysis. Results: Compared with controls, the EG showed significant improvements in sprint (5 m and 20 m) and IAT performance across all age categories (p < 0.01). EPT increased, providing additional opportunities for ball-in-play exposure during matches. The protocol also reduced contact between ball retrievers and players, thereby improving safety and minimizing interruptions. Conclusions: The rapid-restart protocol (RRP) effectively increased EPT and was associated with improvements in sprint and agility performance. Whether these improvements were mediated by changes in match intensity or physiological load remains to be determined. Its simplicity, low cost, and safety benefits make it a practical strategy for coaches, organizers, and the Tunisian Football Federation. This approach may represent a practical organizational strategy for improving match continuity and EPT during youth soccer competitions.