Post-activation performance enhancement (PAPE) is a key objective following regular warm-up routines, especially in sports that rely heavily on sprinting speed and power. Rugby is a team sport characterized by a range of repeated high-intensity efforts, irrespective of positional roles or match demands. In this study, we examined and compared the effects of two different conditioning activities (CAs) on the power- and speed-related abilities of National Team rugby players. Thirteen male rugby union players sequentially performed countermovement jump (CMJ), 30 m sprint, and change-of-direction (COD) tests (pre-testing session) 5 min before executing either one set of six repetitions of 45 cm drop jumps or one set of six repetitions of flywheel eccentric-overload squats. In addition to the sport-specific tests, the muscle mechanical properties of the athletes were also assessed through the use of tensiomyography (TMG). At post-testing sessions conducted 5 and 10 min after the PAPE protocols, no significant changes were observed in any of the assessed variables, either in positions as backs or forwards. However, some meaningful variations were detected at the individual level when using the “true-changes” analysis. Despite some positive individual changes, it can be concluded that these specific protocols did not elicit the expected responses typically observed in other team-sport athletes. Practitioners are encouraged to implement more comprehensive (but not exhaustive) and tailored PAPE interventions prior to training sessions and competitions.