Barcelona welcome AC Milan to the Nou Camp tonight looking to recover from a shock 2-0 defeat to the Italians in the first leg of the Champions League last-16 tie.
Here, we look at the key battles that could determine whether Milan can preserve their lead and advance, or if Barcelona can turn things around and stay in the hunt for a fourth European title in seven years.
CARLES PUYOL v STEPHAN EL SHAARAWY
The 20-year-old El Shaarawy has been in great form for Milan this season and has already scored 18 goals. He will be up against one of the most experienced and respected defenders in world football in Puyol, but if he can get half a chance he is more than capable of tucking away what could prove to be a vital away goal.
ANDREAS INIESTA v SULLEY MUNTARI
Muntari scored his first-ever Champions League goal in the 2-0 victory in the San Siro but a more defensive shift will be expected of him in the return leg. Iniesta had one of Barcelona's best chances to grab an away goal three weeks ago but will be looking to have a more influential evening this time around.
PHILIPPE MEXES v LIONEL MESSI
France international Mexes, and the whole Milan defence, is likely to have their hands full with the world's best player. Messi's performance will be crucial if Barca are to score the three goals required to win the tie in normal time, and if Mexes and company can shackle the Argentinian superstar they will go a long way to securing a spot in the quarter-finals.