Constraint manipulation within representative practice environments may shape players’ behavioral organization. This study examined pre–post changes in blocking behavior following a participation-rule manipulation designed according to the Constraints-Led Approach (CLA) to increase the functional responsibility of the wing blocker during attacks from the outside zones and explored whether these changes differed according to competitive level. Forty-six female U18 volleyball players (16.59 ± 0.88 years) from four Spanish clubs participated in three 6 vs. 6 game situations: pre-manipulation, manipulation, in which the middle blocker was prevented from assisting the wing blocker against attacks from the outside zones, and post-manipulation. Block–ball contact increased overall (Holm-adjusted p < 0.003, Cramer’s V = 0.19), and the distribution of functional outcomes also changed overall (Holm-adjusted p = 0.012, V = 0.18). Decision-making appropriateness showed a significant overall association (Holm-adjusted p = 0.048, V = 0.09). Exploratory within-division analyses showed category-specific changes in functional outcomes. Findings indicate short-term pre–post changes in some blocking dimensions, with small effect sizes. The manipulation may provide a useful task-design strategy for emphasizing wing-blocker responsibility, although further controlled research is required.