Leverkusen - Barcelona coach Luis Enrique is concerned Neymar may be set for a lengthy lay-off after the Brazilian superstar injured his groin before their final Champions League group match.
The defending champions were already through to the Champions League's last 16 for the 12th year in succession and ended their group campaign on Wednesday with a 1-1 draw at Bayer Leverkusen.
Enrique named a mainly second-string team at the BayArena by including only four first-choice players in Marc-Andre ter Stegen, Ivan Rakitic, Jordi Alba and captain Lionel Messi.
An early Messi goal was cancelled out by Javier Hernandez's equaliser, but despite the result, the Germans were eliminated.
With Roma drawing 0-0 at home to BATE Borisov, Leverkusen had to beat Barcelona to progress but the Germans blew their chance and instead will find themselves in the Europa League next February.
Enrique's main concern was Neymar's adductor injury in the final training session in Germany on Tuesday.
The 23-year-old has been in sensational form this season, scoring 16 goals in 18 appearances and crowned La Liga's player of the month for November on the day of his injury.
"It's of course, the bad news from this fixture. It's an unpleasant situation and we have to wait to see what the team doctor says," said Enrique on Neymar's injury.
"We don't know how bad the injury is and we have to hope he recovers quickly in the next few days.
"It's always unpleasant to lose a player through an injury, possibly long term, and we have to hope it's not as bad as feared."
Enrique said he had a "positive feeling" from the way his experimental side coped with a torrent of Leverkusen chances as the Germans peppered the Barca goal with 25 shots compared to the Spaniards' six.
Cameroon teenager Wilfrid Kaptoum made his Champions League debut and midfielder Sergi Samper made only his third appearance at this level.
First-choice Spain internationals Andres Iniesta and Gerard Pique were left in Barcelona while Dani Alves was suspended and Luis Suarez spent the game on the bench.
The team selection was understandable as Barcelona have a busy spell coming up and the Catalans play their Club World Cup semi-final in Japan on December 17.
"I felt positive about our performance," said Enrique, with his side already through as Group E winners.
"I wanted to give the players who have played the most minutes a rest and I saw good signs from us against a team that really had to win. The game was a litmus test for us.
"In the last 16, we'll face whoever we're lucky enough to be drawn with."