Self-myofascial release tools like foam rollers and massage guns are being integrated into athlete warm-ups with increasing frequency, but evidence on their acute effects is limited. Sixteen healthy, trained athletes (23.2 ± 1.3 years; four female) completed three warm-up conditions in a randomised, crossover design separated by >48 h: dynamic warm-up plus foam rolling (FOAM), dynamic warm-up plus massage gun (GUN), and dynamic warm-up alone (CON). After each intervention, participants completed a countermovement jump (CMJ; height and reactive strength index [RSImod]), a 10/5 repeated jump test (RJT), a 20 m sprint, and a knee-to-wall ankle mobility test. Perceived soreness and fatigue were recorded. Linear mixed models and Cohen’s d were used to assess between-condition differences. Relative to CON, FOAM and GUN were associated with reduced CMJ height (d = −0.29 to −0.36) and RSImod (d = −0.40 to −0.52; p’s < 0.05). GUN was associated with significantly impaired sprint time (d = 0.34). There were modest improvements in ankle mobility (left side) following FOAM (d = 0.23, p < 0.05) and lower levels of muscle soreness compared to CON (p < 0.05). Despite some improvements in ankle mobility and muscle soreness with foam rolling, both foam rolling and massage gun use may acutely impair aspects of physical performance compared to a dynamic warm-up alone.<p></p>