Luis Enrique’s side dished out a 7-0 hammering in September’s opening Champions League fixture.
Barca visit Parkhead on Wednesday, with the Hoops needing to upset the odds to remain in European competition in the new year.
Sinclair believes his side can do precisely that, having taken encouragement from draws against Group C rivals Manchester City and Borussia Monchengladbach.
The 27-year-old winger said: “We’ve learned a lot from the 7-0 game. There’s no apprehension.
“It’s very different when you’re playing at home. Being in front of our own crowd will spur us on because those fans are unbelievable.
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Fri, April 15, 2016Express Sport takes a look at some of the greatest players who have appeared in both the English and Scottish top flights in recent times
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“Hopefully now we’re going in with a positive mindset.
“Even when we went away to Monchengladbach we showed the difference when we conceded. We lost the game at home but we went there and drew.”
Celtic have taken the scalp of Barca at Parkhead twice in the last 12 years, enjoying a 1-0 UEFA Cup win in 2004 and a 2-1 Champions League victory in 2012.
Sinclair would love to follow in those footsteps.
He said: “Barcelona have been beaten here before so hopefully we’ll do it again.
“Because we played Kilmarnock on the Friday night we have an extra day’s recovery and that helps.”
Celtic conclude a massive week with the Betfred Cup Final against Aberdeen at Hampden on Sunday.
And Sinclair is loving every moment of it as he thrives under the pressure.
He said: “We’ve another big game on Wednesday against Barcelona and then the cup final on Sunday.
“The games are coming thick and fast and they are big ones as well.
“So there’s a lot of stuff to look forward to.”