As runners-up in their group, neither of the English clubs are seeded and they will have to face a group winner in the last 16.
Monaco, with 11 points, and Porto, with 14, are the two least daunting challenges in the knockout stage and the Gunners and City would be happy with either.
The worst-case scenarios for both are far worse.
Arsene Wenger's side, who went out at this stage last season after drawing Bayern Munich, could meet the Germans again, last year's two finalists Real and Atletico Madrid or Barcelona.
Manuel Pellegrini's team, having scraped through to the knockout phase, will not face Bayern having finished second to them in their group
Instead they could get Borussia Dortmund, poor domestically this season but much better in Europe
Even though Premier League leaders Chelsea comfortably won their group with four wins and two draws they could end up with a tie against Serie A leaders Juventus or Paris Saint-Germain, second in Ligue 1, whose only defeat in six group matches came against Barcelona in the Nou Camp.
Jose Mourinho's side could also get Ukrainians Shakhtar Donetsk, Swiss side Basle or Bayer Leverkusen, third in the Bundesliga.
Seeded group winners will be away in the first legs, to be played on February 17, 18, 24 or 25, with the second legs on March 10, 11, 17 or 18.
The draw for the Europa League will also be made in Nyon, Switzerland, with Liverpool dropping into the competition from the Champions League to join city rivals Everton, Tottenham and Celtic in the last 32.
Brendan Rodgers' side will be unseeded, like Tottenham but not Everton, although two English clubs cannot meet each other until the next round.
Among those in the seeded pot are Inter Milan, Borussia Monchengladbach, Napoli, Fiorentina, Sporting Lisbon and Athletic Bilbao.
Source : PA
Source: PA