Holders and hosts among the names at risk

The UEFA Europa League could reach the round of 16 without the holders as well as the final hosts, with FC Porto and FC Steaua Bucureşti both facing uphill tasks to survive.

Holders Porto took the lead against Manchester City FC, but lost the initiative in the first leg at the Estádio do Dragão, going on to lose 2-1 when Sergio Agüero came on to hit City's winner. Playing in their 50th UEFA club competition game, Roberto Mancini's side will look to slay the Dragons at the City of Manchester Stadium, while in Enschede, FC Twente need only draw to end Steaua's hopes of playing in the final at their home stadium on 9 May, with Steve McClaren's side winning the first leg 1-0 in Bucharest.

Atlético ascendant
Club Atlético de Madrid won the inaugural UEFA Europa League in 2009/10 and are in contention to do so again, with coach Diego Simeone going into the home leg of his side's tie against another of his former clubs, S.S. Lazio, two goals to the good. Ominously, summer Atlético signing Falcao – who set a new record of 17 goals in a single UEFA Cup or UEFA Europa League season with Porto last time out – is speeding up the top scorers rankings, with five goals to his name.

United front
One of the biggest names in the competition is sure to be off the list for the round of 16, with Manchester United FC going into their tie against AFC Ajax at Old Trafford 2-0 up. The statistics make unhappy reading for Frank de Boer's side; United have won all five of their previous European home games against Dutch opponents, while Ajax have won only once in nine trips to England – a 1-0 victory against Nottingham Forest FC which still saw them eliminated from the 1980/81 European Champion Clubs' Cup semi-final on aggregate.

Suárez on edge
The competition could easily lose its top scorer on matchday eight, too; RSC Anderlecht's Matías Suárez struck seven times in the group stage, but crucially failed to find the target against AZ Alkmaar, who beat the Brussels side 1-0 in the Netherlands. Anderlecht are the only club to have won all six of their group stage games this season, but while their visitors are unbeaten in eight European games, AZ have not won in 15 away games in Europe – seven draws and eight defeats – since beating FC Paços de Ferreira 1-0 in the UEFA Cup first round on 20 September 2007.

Metalist edge
A 4-0 first-leg win at FC Salzburg means that FC Metalist Kharkiv are now the 2011/12 UEFA Europa League's top-scoring side with 19 goals. It would take a footballing miracle for them to be denied a tie against Olympiacos FC or FC Rubin Kazan in the next round, with the Greek champions looking to have the best chance of meeting Myron Markevich's side, going into the Piraeus leg of their tie 1-0 up.

Poland's hope
Getting two sides into the round of 32 was a major fillip for Polish football, and both Wisła Kraków and Legia Warszawa go into their return fixtures with hope of making it to the last 16. Despite being reduced to ten men, Wisła snatched a 1-1 draw at home against R. Standard de Liège, and while Legia were twice pegged back by Sporting Clube de Portugal, they know they can score goals against Ricardo Sá Pinto's side as the action shifts to Lisbon.