Neymar and Kylian Mbappe were both doubtful for Wednesday's clash against the Reds after picking up knocks in the international break.
Both players started the encounter as Mbappe played a key role in Neymar's goal in the first half.
The Brazilian forward has now revealed he was not completely fit to face the Premier League outfit.
"I was not 100 per cent," Neymar told reporters, via L'Equipe.
"But it was an important match so, injured or not, I had to be there."
Neymar also became the highest scoring Brazilian in Champions League history with his goal against the Reds, overtaking former AC Milan star Kaka.