Lionel Messi was stretchered off with a knee injury as Barcelona drew 0-0 with Benfica at the Nou Camp, a result which sees Celtic go through at the expense of the Portuguese from Champions League Group G.
The club later confirmed on its Twitter site that the injury was only bruising to the left knee, but added that the Argentine "is still awaiting more tests to determine the extent of the injury".
Benfica needed only to match Celtic's result against Spartak Moscow and they wasted a number of excellent chances against a weakened Barca, especially in the first half and were to rue them as Celtic snatched a 2-1 win over Spartak Moscow.
Messi was brought on as a second-half substitute but went down clutching his knee late on in the game.
The Catalan side cruised through the group stage with just one defeat, away to Celtic, in what has been a prolific start to the season where domestically they have made a record start with 13 wins from 14 games.
Fans turned up hoping to see Messi match or better Gerd Mueller's record of 85 goals in a calendar year but in the end the night finished on a sour note with the Argentine still a goal behind.
Barca chose to rest the bulk of the regular side and took the opportunity to blood youngsters in the true spirit of the club which takes such a pride in the production line from their Masia academy.
Still at the back there was the steadying presence of Carles Puyol at centre half, while Alex Song was in the middle and David Villa in the attacking trident.
Benfica's task of toppling the Catalan giants was made more difficult by the loss of a number of important players, including Pablo Aimar, Enzo Perez and Eduardo Salvio.
Although with some unfamiliar faces in tehir line-up, Barca set out from the start to play the same way with quick, short passing but a combination of nerves and inexperience saw them struggle to move upfield and when Benfica broke they caused plenty of danger.
While Barca were building play with 15 to 20 passes strung together, just one ball from Ola John after 11 minutes should have seen Benfica go ahead. Rodrigo Moreno was put through on goal but with just Jose Pinto to beat he slotted past the post.
The Barca defence looked too flat against the pace of the Benfica forward line and Rodrigo Lima headed wide from close range from a Nolito cross.
At the other end Barca were also making dangerous runs, especially through Cristian Tello but they were lacking the final ball or were caught offside as Benfica's defence pushed forward.
Rafinha played the ball back into the goalmouth after 24 minutes but Ezequiel Garay cleared on the line.
The danger to the Barca goal increased in the run-up to half time as a Nolito pass put Lima clear down the left channel but Pinto got his fingertips to the ball and deflected it onto a post.
Then John cut inside Adriano Correia but Pinto again came to the rescue to parry his shot from 10 metres and it was not long before the home fans began to chant the name of Messi.
Straight after the restart Nolito was guilty of another glaring miss but Barca began to take more of a grip on the game and Sergi Roberto impressed in midfield as he began to direct play.
They threatened in attack mainly through Tello while Villa appeared out of sorts and failed to take advantage of a number of half-chances.
Messi came on for the final half-hour but in his one chance to equal Mueller's record he attempted to round Artur who clawed the ball away. When Messi retrieved it he twisted and picked up the injury which ended his game.