Neymar's role in Scott Brown's sending off has been criticised by Neil Lennon and Gordon Strachan over the past couple of days but it was his performance that attracted greater scrutiny in Spain.
The Brazilian, a £48m summer signing from Santos, has endured an underwhelming start to his career in Barcelona, scoring once in eight outings. He did, however, play a prominent role in the midweek win, tumbling under a challenge from Brown and making great play of the Celtic captain's foolish flick. Neymar also passed up a fine chance to add some gloss to the scoreline when his low shot was thwarted by Fraser Forster in the closing stages.
Despite the youngster's slow start to life in Catalonia, Andres Iniesta has no doubt he will come good. "He has a lot to improve, but he is a different kind of player and he will be very helpful to us this year," said the Spanish internationalist. "You have to remember that he's very young and he has a lot to improve upon, but it is clear that Barca have a good player for years to come.
"The team is continuing to grow in the idea of how we'd like to play together and in confidence. I think our hopes and eagerness are intact and we hope to continue like this."
Not everyone in the Celtic camp was critical of Neymar, either. Virgil van Dijk preferred to concentrate on his many attributes. "He's so quick and flighty, he's always on the go," said the Dutch defender. "He didn't score but he works so hard that it benefits his team so much. It was a great game for me to continue to learn. I'm still improving and that was a great experience."
That knowledge will be tested when Ajax visit on matchday three but Celtic will not have to quell the threat of Bojan Krkic, with the attacker likely to be absent for at least a month after sustaining a tear in a hamstring after five minutes of the Dutch champions' weekend thrashing of Go-Ahead Eagles.