Faced with hazardous trips to Napoli and Marseille respectively, out-of-form Chelsea and Inter Milan will need to watch their step as the Round of 16 of the UEFA Champions League continues this week with the last four first-leg ties.

Also in action in the two other games are big guns Bayern Munich and Real Madrid, both former winners of the competition along with Inter and Marseille.

This week’s fixtures
Tuesday 21 February
CSKA Moscow-Real Madrid (18:30 CET)

Wednesday 22 February
Marseille-Inter Milan
Basel-Bayern Munich

Match of the day
Napoli-Chelsea, Stadio San Paolo, Naples, 20:45

Just a week after Arsenal were crushed 4-0 at AC Milan, an equally out-of-sorts Chelsea face a daunting Italian job of their own when they travel to Naples to take on one of Serie A’s most entertaining outfits. The triumvirate formed by Marek Hamsik, Ezequiel Lavezzi and Edinson Cavani have hit 35 league goals between them since the start of the season and are determined to add a few more as Napoli go in search of their main objective this season: Champions League success. Unbeaten in 11 matches at their San Paolo citadel since making a long-awaited return to Europe in 2008, the Neapolitans will be hampered by the absence from the dugout of coach Walter Mazzarri, who is suspended for both legs. 

Opposite number Andre Villas Boas has bigger problems to ponder after Sunday’s 1-1 home draw with Birmingham City in the FA Cup extended his spluttering side’s winless run to four games. With the Blues currently occupying an unaccustomed fifth place in the Premier League and several key players reportedly questioning his tactics, the under-fire Portuguese boss is grateful for the backing of owner Roman Abramovich. Chelsea also have some unfavourable statistics to contend with – in ten visits to Italy they have won just once, drawing five times and losing four.

The other matches
CSKA Moscow-Real Madrid
UEFA Cup winners in 2005, the Muscovites are unbeaten in five games against Spanish opposition and qualified for the last 16 thanks to their fine away form in the group phase, ending the section with a crucial 2-1 win at Inter Milan. The Russians were beaten twice at home, however, and can afford no slip-ups against a rampant Real side that has just notched its 18th victory in 19 games in La Liga and its eighth on the trot. Add to that Madrid’s flawless record in the group phase, with six wins out of six, and the rich vein of form of Cristiano Ronaldo and strike partner Karim Benzema – four goals and four assists in the competition so far – and the scale of CSKA’s task becomes clear. With Pavel Mamaev and Kirill Nababkin both out through suspension, the hosts are banking on Seydou Doumbia to add to the five goals he has scored to date.

Marseille-Inter Milan
Little has gone right for Inter since downing arch rivals AC Milan in the city derby. In collecting a solitary point in their five last Serie A outings, Claudio Ranieri’s side have suffered heavy defeats to Roma and Bologna and contrived to lose to bottom club Novara, and have now lost ten times in all in the league. The absence of defensive cornerstone Walter Samuel goes some way to explaining that run, though Inter have problems at the other end too, having gone goalless in their last three games. The fourth coach to occupy the Nerazzurri hotseat since Jose Mourinho’s departure, Ranieri knows he has little margin for error.

In contrast, Marseille have recovered their poise in the league and have a respectable record against Italian clubs, with five wins, four draws and five defeats. The weekend’s 1-1 home draw with Valenciennes was a disappointment, however, and coach Didier Deschamps will have to do without the injured Loic Remy, l’OM’s chief attacking threat. The two sides, both former European champions, faltered at home in the group phase, each losing twice in front of their own fans but making up for it by collecting seven points on the road.

Basel-Bayern Munich
A one-time youth coach at Bayern, Basel boss Heiko Vogel will need to shore up his team's defence if they are to pull off one of the biggest upsets in the club’s history. Unbeaten in 13 games in all competitions since losing to Benfica 2-0 in October, the Swiss nevertheless conceded ten goals in the group phase, more than any other side in the last 16. Bayern have been anything but convincing away from the Allianz Arena lately, however, as lowly Freiburg proved in holding them to a goalless draw at the weekend. Now four points adrift of leaders Borussia Dortmund in the Bundesliga, the Bavarian giants have their sights set on one thing only: contesting the Champions League final at their home stadium in May.

Player to watch
Cristiano Ronaldo scored his 28th league goal of the season against Racing Santander on Saturday, in only Madrid’s 23rd game. The Portuguese has now struck 34 in all competitions this season, taking his overall tally in a Madrid shirt to 121 in a mere 123 matches. Now level with the legendary Juanito as the club’s 13th-highest all-time goalscorer, Ronaldo is just nine short of Michel in tenth, but still well behind Raul, who stands at the top of the chart with 202.

The stat
7 - The number of former European Cup and Champions League winners who have reached the last 16, the same as in the last three seasons but three less than in 2005 and 2006.

What they said
“I like Inter and Chelsea a lot and their fans too, but I’d prefer them to support their teams and their coaches rather than chant my name. I am the past, a very good past when we won a lot of trophies, but today is the present and I’m not there anymore.” Real Madrid coach Jose Mourinho, formerly in charge at Chelsea and Inter Milan.

Have your say
Will there be an English club in the last eight?