Purpose: The purpose of this study was to assess neuromuscular performance capabilities over an in-season mesocycle in early-career professional soccer players and examine the relationship with training workload. Methods: Neuromuscular performance capabilities (isometric knee extensor: peak force, rate of force development, and peak twitch force) of 12 professional soccer players were assessed weekly over a 6-week period. Training and match workload were also recorded over the same period for each player (high-intensity running distance). Changes in neuromuscular performance and workload variables were analyzed. Results: There was evidence of fluctuations in neuromuscular performance capability over the mesocycle that reached statistical (P < .05) and practical (13.3% [peak-to-peak]) significance alongside interweek heterogeneity in training and match workload (∼17.5% [coefficient of variation], P < .05). Congruence among fluctuating patterns of intramesocycle training load and concomitant neuromuscular performance responses was noted over time for acute training load and acute:chronic workload ratio with peak force and rate of force development. Conclusion: Neuromuscular performance capabilities fluctuate over an in-season mesocycle and are influenced by high-intensity running workload, emphasizing the need for acute monitoring in elite soccer players.