We have had so far a tight and intense competition, says Giorgio Marchetti, UEFA's director of competitions
The Champions League will resume in August after being halted in March due to the COVID-19 pandemic with a 'Final Eight' tournament being held in Lisbon after the remaining second-leg games from the last 16 ties are decided.
The revamped Champions League will feature a tennis-style seeding system for the last-16 knockout phase, UEFA said.
Defending champions Bayern Munich must face Diego Simeone's Atletico Madrid after they were drawn together in Champions League Group A alongside Salzburg and Lokomotiv Moscow.
UEFA president Aleksander Ceferin said he expected matches to be played without fans, although there was a small chance that could change.
The top four European leagues will each have four guaranteed places in the Champions League group stage from 2018/19 under changes announced by European soccer body UEFA on Friday.
News of all that's transpired on and off the football field
Defending champions Portugal and the last two World champions, France and Germany, were thrown together in what German coach Joachim Loew described as the group of death following a lop-sided and complicated Euro 2020 draw on Saturday.
Wednesday evening's dramatic Euro 2016 group stage finale concluded an engrossing opening round that was tight and tense to the last as the expanded new-look European Championship passed its first test.
Italy manager Antonio Conte named his provisional squad for the European Championship on Monday, and his selection was notable as much for the player he left off as for those he chose.
Midfielder Riccardo Montolivo missed out on his second straight major tournament due to injury on Tuesday while Daniele De Rossi was included in Italy's 23-man squad for next month's European Championship in France.