Lionel Messi missed out on a chance to match Gerd Mueller's record of 85 goals in a calendar year as he was injured during Barcelona's draw with Benfica.
Messi, who hurt his left knee in a collision with Benfica keeper Artur, was taken off 30 minutes after coming on as a second-half substitute.
Benfica knew a win would see them finish second behind Barca in Group G.
But the Portuguese side missed several early chances and the 0-0 draw meant Celtic qualified instead.
Messi, who has scored 84 goals so far in 2012, had been left on the bench by Barca, who were already guaranteed to go through as group winners.
The 25-year-old Argentina international has four matches left this year to overhaul Mueller's tally - La Liga games against Real Betis, Atletico Madrid and Real Valladolid, and a Copa del Rey tie with Cordoba.
FC Barcelona's official Twitter account tweeted after the Benfica game: "Messi has a bruise on the outside of his left knee. He'll undergo further tests to determine the exact extent of the injury."
Elsewhere, Galatasaray pipped CFR Cluj to second place behind Manchester United in Group H after a dramatic late win over Braga.
The Turkish side, who trailed to Mossoro's first-half goal, levelled through Burak Yilmaz's header and triumphed when Aydin Yilmaz tapped home after Quim failed to hold on to a shot.
That meant they finished above Cluj on the head-to-head rule, leaving the Romanian side to settle for a Europa League spot.
Juventus edged a tight game against Shakhtar Donetsk to join the Ukrainians in qualifying from Group E.
The Italian side, who needed a point to finish above Chelsea, scored the only goal of the game when Stephan Lichtsteiner's cross went in off Shakhtar defender Olexander Kucher.
Juventus go through as group winners, while Donetsk finish second above the Blues because of their head-to-head record - they scored more goals at Stamford Bridge than the London club managed at the Donbass Arena.
Bayern Munich and Valencia were already sure of their progress from Group F before the final round of matches and both teams rounded off their group campaign with wins.
The German side thrashed BATE Borisov 4-1 to ensure they went through as group winners, while Valencia beat Lille 1-0 in France. BATE already knew they would finish third.