I'm not suggesting you've made up that bullshit, but someone has.
Performance not materially affected, but likelihood of injury increased according to this study :
ABSTRACT
Recovery duration may be too short during the congested fixtures of professional soccer players with regard to maintaining physical performance and a low injury rate.
To analyze the effects of 2 matches per week on physical performance and injury rate in male elite soccer players.
Cohort study; Level of evidence, 3.
Match results, match-related physical performance, and injuries were monitored during 2 seasons (2007-2008 and 2008-2009) for 32 professional soccer players in a top-level team participating in the UEFA (Union of European Football Associations) Champions League. Total distance, high-intensity distance, sprint distance, and number of sprints were collected for 52 home matches. Injuries and player participation in matches and training were recorded throughout the full season.
Physical performance, as characterized by total distance covered, high-intensity distance, sprint distance, and number of sprints, was not significantly affected by the number of matches per week (1 versus 2), whereas the injury rate was significantly higher when players played 2 matches per week versus 1 match per week (25.6 versus 4.1 injuries per 1000 hours of exposure; P < .001).
The recovery time between 2 matches, 72 to 96 hours, appears sufficient to maintain the level of physical performance tested but is not long enough to maintain a low injury rate. The present data highlight the need for player rotation and for improved recovery strategies to maintain a low injury rate among athletes during periods with congested match fixtures.
Full paper : https://www.researchgate.net/public..._Week_on_Physical_Performance_and_Injury_Rate