Arsenal must press as they have never pressed before and Tottenham must wing it if North London is to have a continuing role to play in the capital's quest for a first European Cup. Chelsea, who came closer than anyone to that Holy Grail when losing the final to Manchester United on penalties in 2008, have much the easiest draw of the three local rivals and will be expected to dispose of Copenhagen in a tie that does not begin until next week (when United play Marseille). For Arsenal and Spurs, the draw for this first knockout round has brought glamour but a greater risk of elimination against the league leaders in Spain and Italy respectively.
There is a tendency in European competition to judge opponents on past glories rather than current stature, overrating, say, a Juventus, Ajax or Benfica on the basis of what was achieved some years ago with completely different players and coaches. Unfortunately for the North London pair, that does not apply to either Milan, who are on top of the table, or Barcelona, who are on top of their game as well, so much so that Pep Guardiola's side are now being compared to the greatest club teams of all time.
Tottenham have fond, albeit distant memories of Tuesday's opponents, having beaten them in the semi-final of the Uefa Cup almost 40 years ago before winning the trophy. For Arsenal, memories and wounds are much fresher. It is, after all, less than a year since they somehow survived one of the most one-sided first halves ever suffered on their own ground and emerged with a 2-2 draw against Barcelona, only to concede four goals to Lionel Messi in the second leg (a letter published in The Independent asked how your correspondent could have been so mean-spirited as to award Messi only nine marks out of 10).
Containing the little sprite, who went into last night's game against Sporting Gijon with 37 goals in 31 games this season, will again be but one of their problems. Gaining sufficient possession to attempt their own close-passing game will be another, and it is here that they must improve at the Emirates on Wednesday, closing down and pressurising Barça much more effectively, ideally before they have moved the ball as far as the metronomic Xavi and Andres Iniesta in midfield, let alone Messi. Once the latter starts running at a defence that has been prone to leakage all season, then Arsenal really will be in trouble.
It is bizarre to think that but for a couple of lapses in concentration just after half-time in the home leg last time, Arsène Wenger's side would have won a game in which he admitted that Barcelona's opening spell was the best football he had ever been up against. "We are in better form going into this game than we were last year and in a better shape physically," he told Arsenal TV Online yesterday. "I believe we are more mature as well. Having said that, I concede as well that Barcelona is even stronger than last year. But I think we can give them a very interesting test. We are not favourites, so it takes a little bit of the pressure off our shoulders. On the other hand we are very ambitious and we want to show that we can knock them out."
The positives for Tottenham include their own vibrant form in Europe this season; and the familiarity and confidence that beating Milan's co-tenants Internazionale has inspired. The Tottenham manager Harry Redknapp always approaches these games by balancing the pluses with due respect for the opposition, which involves no insincerity in praise of Milan. "As for lessons learned so far, you have to go away from home and keep it tight," Redknapp said on Friday. "We have made some fantastic comebacks but they don't happen all the time. What we need to be from the start is concentrated and focused."
Where Spurs will hope to profit, home and away, is by attacking at pace down the flanks in the manner that confounded Inter in the second half at the San Siro and throughout the game at White Hart Lane. Aaron Lennon can play his part and will have to do so if Gareth Bale is unfit, although the flying winger's chances have improved. Redknapp would also want to have Luka Modric pulling strings in central midfield, which may not be possible.
Milan, under their unfashionable coach Massimiliano Allegri, have been hard hit by injuries recently, although two key figures in defender Alessandro Nesta and Andrea Pirlo, the playmaker from deep, should be fit. Mark van Bommel is ineligible but further forward they have a potentially formidable attacking trio in the rejuvenated Zlatan Ibrahimovic, Robinho and the young Brazilian Pato.
A tentative conclusion would be that by the time of the quarter-finals, Chelsea will again be carrying London's hopes alone.
Milan v Tottenham Hotspur is on Sky Sports 2 on Tuesday. Arsenal v Barcelona is on ITV1 on Wednesday (both 7.45pm kick-offs)
Champions' League Last 16
Valencia v Schalke (7.45pm, Sky Sports 4)
Valencia are in the top four of La Liga and should build a lead against schizophrenic Schalke, who are stuck in the bottom half of the Bundesliga but were winners of their group.
Roma v Shakhtar Donetsk (7.45pm, Sky Sports 2)
Eastern Europeans can be caught out during their winter break and Shakhtar, who have reached this stage for the first time, must ensure it does not happen against Claudio Ranieri's side.
Europa League Last 32
Aris Salonika v Manchester City (6pm, ITV4)
Aris may sound unfashionable opposition but they have a remarkable home record in European games, being unbeaten in all 24 of them, the first of which was against Chelsea in 1970.
Rangers v Sporting Lisbon (8.05pm, ESPN)
Rangers will come up against their former midfielder Pedro Mendes in a Sporting side showing better form this season away than at home.
Sparta Prague v Liverpool (8.05pm, Five)
Kenny Dalglish will relish a return to European competition as Liverpool, unbeaten abroad this season, make only their second appearance in the Czech Republic.
NB Chelsea (away to Copenhagen) and Manchester United (in Marseille) play their ties on 22/23 February.