Both of those competitions have viewed format changes, with expansions in the amount of participating groups, introduction of new rounds, and changes in qualification standards over the years. The group phase was played from September to December, although the knockout stage started in February, with matches generally performed on Tuesday https://k-o-nh-c-i39628.webdesign96.com/36790521/little-known-facts-about-what-are-the-uefa-champions-league-and-uefa-europa-league