Champions League Last 16 Draw: Nightmare Scenarios for Arsenal and Chelsea

On Friday the draw for the knockout stages of the Champions League will take place in Nyon, Switzerland, with the 16 remaining clubs set to learn their second-round opponents.

With Manchester United and Manchester City both relegated to the Europa League, the Premier League challenge will be brought by Arsenal and Chelsea.

Both London clubs won their groups, and will hence face an opponent who finished runner-up in theirs. Here are the nightmare scenarios.

Arsenal/Chelsea vs. AC Milan

AC Milan are unquestionably the team to avoid for Arsenal and Chelsea. The Italian champions lost just once in the group stages, and there's no shame in a 3-2 reverse when the opposition is Barcelona.

Milan are unbeaten in Serie A since early October and finding goals easy to come by this season. Zlatan Ibrahimovic and Robinho would provide either London club with something to worry about.

In midfield Milan are blessed with plenty of big-game experience, with the likes of Clarence Seedorf, Mark van Bommel and Massimo Ambrosini veterans of the Champions League stage.

In a tight two-legged tie level heads are at a premium.

Arsenal/Chelsea vs. Napoli

Napoli's one slip in a difficult group was a 3-2 defeat in Germany to second favourites Bayern Munich.

The Champions League newcomers out-gunned Manchester City and Villarreal to reach the last 16, and in Edinson Cavani, boast one of the hottest strikers in Europe. Cavani scored four times in the group stage and will be a feared opponent to whoever draws Napoli on Friday.

Also in Napoli's favor is the intense atmosphere created in their home stadium, which will make for an intimidating experience for their last-16 opponents.

Arsenal and Chelsea, having seen Manchester City held at home and beaten away by the Italians, will be keen to avoid them in the draw.

Arsenal vs. Bayer Leverkusen

You can't draw a team you were grouped with in the last 16, which means Chelsea will avoid Bayer Leverkusen and their old friend, Michael Ballack.

If Arsenal get the Germans, you'd expect them to progress, but it's worth bearing in mind Leverkusen won all three home games in Group E. They beat Chelsea, 2-1, in Germany thanks to a last-minute winner.

The Germans have been patchy in the Bundesliga, however, with the most shocking result a 4-1 home loss to Koln. They were also swept away, 3-0, by Bayern Munich.

That said, in Eren Derdiyok, they boast a player who's capable of doing things like this.

Dream Draw

Manchester United may have struggled against them, but you can guarantee Arsenal and Chelsea would be very happy to pull Basel out of the hat on Friday,

The Swiss side are defensively vulnerable and should be easily picked off by either Premier League club.

Draw Details

The draw takes place on Friday, at the House of European Football in Nyon, Switzerland. The Champions League last 16 draw is scheduled to begin at 1 p.m. CET (12 p.m. GMT, 8 a.m. EST, 5 a.m. PST), and will be followed by the last 32 draw for the Europa League.

Bleacher Report's Michael Cummings will be providing a live blog of proceedings. FOLLOW IT HERE!