Manchester City’s gaffe of seemingly not knowing the rules could prove costly as they face a major obstacle in today’s round of 16 draw in the Champions Leauge, regardless who they are pitted against.

Manager Manuel Pellegrini suggested after the 3-2 victory at holders Bayern Munich Tuesday that he believed a 5-2 win had been necessary to top the group ahead of Munich and that he therefore did not bolster his attack after the third goal in a comeback from 2-0 down.

But in reality a 4-2 would have been sufficient to go top and City may pay a big prize for this error, although a depleted lineup showed they were at least originally content with being runner-up.

As group winners they would have played Schalke, Bayer Leverkusen, AC Milan, Galatasaray, Zenit St Petersburg or Olympiakos in the first knockout round.

While none of these are pushovers, City’s second place in the group confronts them with an even more daunting task against either record winners Real Madrid, mighty Barcelona, 2013 runners-up Borussia Dortmund, high-flying Atletico Madrid or big-spending Paris Saint-Germain.

Arsenal, who crashed 6-3 against City in the Premier League Saturday, are by no means better off as they will face one of the same teams apart from Dortmund - with title holders Bayern Munich their fifth option instead.

Arsenal and City may be the only teams to beat Munich in the elite event in 2013, both in Germany, and in order to lift the trophy a team sooner or later has to overcome the most difficult opposition.

But a look at the teams shows that it has rarely seemingly made such a difference whether a team won a group or finished second. The group winners are Real, Barca, Atletico, Bayern, Dortmund, Manchester United, Chelsea and PSG. The runners-up are City, Arsenal, Schalke, Leverkusen, Milan, Galatasaray, Olympiakos and Zenit St Petersburg.

That is because group winners are seeded and play second-placed teams, and have the home field advantage in the return leg. Teams from the same group can’t meet again in the last 16 and teams from one league are also kept apart, which leads to the difficult tasks lying ahead of City, Arsenal and others.

“Obviously we are going to get a tough draw, finishing second, but the fact we can come to Bayern and win says a lot about the quality in the squad,” City forward James Milner said.

The United camp was certainly aware of the importance of finishing top of the group, with midfielders Phil Jones and Tom Cleverley naming first place from a 1-0 over Shakhtar Donetsk “massive” and Wayne Rooney saying it was “the most important thing”.

But all the favourites face at least 180 minutes of hardship to make sure they advance to the quarter-finals, and the example of Munich shows that there can be plenty of obstacles.

Munich will not fancy a trip to probably freezing St Petersburg in February and have also not forgotten that they were routed 4-0 there in the 2008 UEFA Cup semi-finals.