The Scottish champions produced a massive upset when they knocked off the Catalan giants 2-1 at Parkhead and Messi, who netted a late consolation for his side, believes that Neil Lennon's men were very lucky to come away with maximum points.
"They were very lucky. It's a shame but we just couldn't do anything about it," he told the Daily Record.
"We did everything in the game but just couldn't get past them.
"Celtic came at us twice and got two goals from it. When they scored they just locked their defence.
"The first goal (Victor Wanyama in the 21st minute) from the corner arrived because they are a bigger team than us - it was the same as their goal in the Nou Camp.
"The second goal (Tony Watt in the 83rd) was our own fault.
"We did everything well and made good chances but the ball just didn't go in."