Lionel Messi was carried off on a stretcher as Barcelona played out a goalless draw with Benfica, who drop out of the Champions League.
Benfica have not beaten Spanish opponents in 30 years but came close to opening the scoring at Camp Nou after 12 minutes when former Real Madrid striker Rodrigo bent a shot just wide of Jose Manuel Pinto's post.
The Portuguese side had the better of the first-half against Barcelona, who named 14 academy products in the squad and began the game with Messi on the bench.
Rafinha saw a header cleared off the line but it was Benfica who looked most threatening as Lima's shot was tipped onto the post by Pinto.
The score remained goalless at half-time after Ola John struck into the side netting from a dangerous position but the Benfica pressure continued after the restart.
Former Barcelona winger Nolito fired just wide two minutes into the second half and Tito Vilanova responded by introducing Messi - who has scored 84 goals in 2012 - before the hour mark.
The substitution lifted the Catalan giants and Messi tested Benfica goalkeeper Artur Moraes with a series of free-kicks and a shot from a tight angle with five minutes remaining.
But the evening ended badly for the Argentinian as he was carried off the pitch on a stretcher with a serious knee injury, leaving his chances of beating Gerd Muller's 1972 record of 85 goals in a calendar year in some doubt.
Barcelona finished the game with 10 men but held off Benfica who drop into the Europa League after finishing third in Group G.