Premier League leaders Chelsea play Paris St Germain in the Champions League last-16 second leg at Stamford Bridge on Wednesday with the tie level at 1-1.

Here, Press Association Sport looks at some of the talking points.


The first leg on February 17 was overshadowed by an incident of racism on the Paris Metro, when a black commuter was blocked from boarding a train by Chelsea fans prior to the match. Five Chelsea fans were suspended as a result of the incident, which was caught on video, and anyone found guilty of the abuse faces a life ban. Souleymane S, the French-Mauritian victim, was invited to Stamford Bridge for the return, but his lawyer said it was "too early" for him to attend, declining the invitation.


Chelsea had six days to prepare for the first leg and seven for the second as the fixtures came after FA Cup weekends without the Blues, who were eliminated by League One Bradford. That has allowed Jose Mourinho to finely tune preparations and focus on foiling PSG's vaunted attack. Holes were exposed at the Parc des Princes, but Chelsea emerged with a favorable 1-1 draw. Expect the holes to have been filled at Stamford Bridge. Mourinho will not want a repeat of the drama which saw Demba Ba score a last-gasp goal to send the Blues through last term.


Nemanja Matic returns from suspension after missing the Capital One Cup win as part of his two-match ban. The Serbia midfielder's importance to Chelsea cannot be underestimated – he shields the defense and allows the likes of Cesc Fabregas to flourish. Chelsea had to swallow their pride in re-signing Matic, who moved to Benfica as part of the deal that brought David Luiz to Stamford Bridge. Now Luiz is in opposition at PSG and must show his value for them.


Chelsea have lost three times this season, but only once at home, 4-2 to Bradford, having led 2-0. PSG are aiming to inflict defeat on the Blues to reach a third straight quarter-final. The 2012 winners Chelsea are looking to reach the last eight for the seventh time in nine campaigns. Mourinho has reached the semi-finals for four straight seasons (three with Real Madrid and last season with Chelsea) and is bidding to become the first coach to win the competition with a third club (after Porto in 2004 and Inter Milan in 2010).


Diego Costa has not scored in six games. The prolific marksman has found the net 17 times in 20 Premier League appearances, but is yet to score outside of the competition – his strike at Wembley was recorded as an own goal for Spurs defender Kyle Walker – and last netted a double strike against Swansea. Costa has shown his willingness to work for the team, earning praise from Mourinho, but he will be expected to deliver goals on the big occasion too. PSG have a host of attacking players – Zlatan Ibrahimovic, Edinson Cavani and Ezequiel Lavezzi to name three – who could outshine Costa and co. Blues fans will hope Costa delivers.