The group stage of the UEFA Champions League 2021-2022 season finally concluded with a match between Villarreal and Atalanta on December 9 (Thursday). Villarreal qualified for the Round of 16 after defeating Atalanta 3-2, and they will be joined by 15 other teams for the first knockout round draw in Switzerland on Monday, December 13th. It's possible that PSG and Man United could meet in the Round of 16 of the competition. Let's have a look at the Round of 16 draw scenario for the Champions League 2021-2022.   Group Winners of Champions League 2021-2022 The eight group winners are Manchester City (group A), Liverpool (group B), Ajax (group C), Real Madrid (group D), Bayern Munich (group E), Manchester United (group F), Lille (group G), and Juventus (group H).   Manchester City won Group A with a total of 12 points. The defending English Premier League Champion won four of their six group stage matches. Liverpool finished first in Group B with 18 points after winning all of their games. The Dutch league winner Ajax also won all of their matches in Group C, finishing with 18 points. Real Madrid were stunned at the Bernabeu by Sheriff Tiraspol, but the most successful European team returned to the top of Group D with 15 points.   Bayern Munich won Group E with a total of 18 points. Manchester United got the first position in Group F with 11 points, while Lille took top place in Group G with 11 points. Juventus took the first position in Group H with 15 points. Group Runners-up of Champions League 2021-2022 Paris Saint-Germain (group A), Atletico Madrid (group B), Sporting CP (group C), Inter Milan (group D), Benfica (group E), Villarreal (group F), Red Bull Salzburg (group G), and Chelsea (group H) are the eight group runners-up. PSG finished second in Group A with 11 points. They won three games, drew two games, and lost one. Atletico Madrid finished second in Group B with 7 points. They only won two games, drew one, and lost the other three. Sporting CP finished second in Group C after winning three matches and losing three. The Italian Serie A Champion Inter Milan finished second in Group D with ten points. Portuguese team Benfica defeated Barcelona to finish second in Group E. Spanish team Villarreal finished second in Group F with ten points. Red Bull Salzburg finished second in Group G with ten points. The defending Champions League champion Chelsea finished second in Group H with 13 points. They were two points behind Italian giants Juventus. Potential Round of 16 opponents for PSG and Man Utd Each group's winners are seeded, while the group's runners-up are unseeded. Seeded teams are matched against unseeded ones. Teams from the same group or football federation are not allowed to play each other in the Round of 16.   As per the aforementioned rule, Ajax, Bayern Munich, Juventus, Liverpool, Manchester United, and Real Madrid could be PSG's Round of 16 opponents. Therefore, Lionel Messi's Paris Saint-Germain is expected to face a difficult opponent in the next round. On the other hand, PSG, Atletico Madrid, Benfica, Inter Milan, RB Salzburg, and Sporting CP might well be Manchester United's Round of 16 opponents. Given Man Utd’s current form, they would have a tough battle in the first knockout round of the Champions League 2021-2022 season.   Mathematically, Ronaldo's Manchester United has a 20% probability of facing Messi's PSG in the Round of 16. It would be a huge match if these two teams were drawn against one other in the first knockout round.    Aside from that, Atletico Madrid, Chelsea, and Inter Milan may face a difficult opponent in the Round of 16 as well. Verdict   Given the outcome of the Champions League group stage in the 2021-2022 season, there is a good chance that the next round will include some tough matches. If Paris Saint-Germain and Manchester United meet in the Round of 16, it will be the most anticipated match of the tournament. Because fans will be able to see Messi and Ronaldo play against each other for their new teams. At least two more fascinating Round of 16 matchups are possible in this draw. Overall, the first knockout round of the Champions League 2021-2022 is predicted to be an exciting event in February and March of next year.