Continental giants Bayern Munich and Arsenal enter the Champions League at the play-off stage this week knowing that failure to reach the competition's lucrative group stage is unthinkable. Arsenal's failure to finish higher than fourth in last season's Premier League came back to haunt them when they were drawn to face Serie A surprise package Udinese in their two-legged play-off. The London club endured a difficult summer marred by uncertainty surrounding the futures of star duo Cesc Fabregas, who finally sealed a deal with Barcelona late Sunday, and Samir Nasri, and fan concerns were hardly eased by their team's performance in drawing 0-0 at Newcastle on the opening day of the Premier League season. The Gunners can draw some comfort from the fact that the Udinese squad that lit up Italy last season has since been weakened by the departures of Chilean winger Alexis Sanchez, Colombian defender Cristian Zapata, and Swiss midfielder Gokhan Inler. Nevertheless, the pressure is on Arsene Wenger's side to claim a positive result in Tuesday's first-leg at the Emirates Stadium before travelling to Italy for the return. The pressure is arguably even greater on four-time European champions Bayern Munich as they prepare to take on FC Zurich. Jupp Heynckes has endured an unconvincing start to his latest spell in charge of the Bavarians, but with this season's Champions League final being held at Munich's Allianz Arena they are targeting a run all the way to the final. However, the 2010 runners-up may be missing injury-plagued Dutch winger Arjen Robben for the first-leg after he sat out Saturday's Bundesliga win at Wolfsburg. Zurich travel to Germany for Wednesday's clash buoyed by a 2-1 domestic win at Basel on Saturday. Lyon are hoping to take their place in the group stage for the 12th consecutive season, but with the French club going through a period of transition, they could scarcely have asked for a tougher draw than Rubin Kazan of Russia. Lyon need a good result at the Stade de Gerland before the return leg in Tatarstan, and new coach Remi Garde is upbeat despite seeing his side struggle to a 1-1 draw against unfancied Ajaccio in Ligue 1 on Saturday. "My lads got the minimum acceptable result from the evening and their performance pleased me," said former Lyon and Arsenal player Garde after the game. "The match waiting for us in the Champions League on Tuesday night is shaping up as a similar encounter only tougher and more defensive." Rubin are already two-thirds of the way through their domestic season and so should be the sharper side. However, they have selection problems, with Alexander Ryazantsev, Carlos Eduardo, Cristian Ansaldi and Alexander Orekhov all carrying injuries. Fourth in Spain's Primera Liga last season, Villarreal are favourites to beat Odense of Denmark despite losing Santi Cazorla to Malaga over the summer. Other stand-out ties include two-time European champions Benfica at Twente Enschede of the Netherlands and FC Copenhagen -- who reached the last 16 last season - against Czech champions Viktoria Plzen.