The ex-Parkhead flop dismissed the achievements by Brendan Rodgers and his side because they’ve come against the likes of “Ross County and St Johnstone”.
Cascarino, who had a failed eight-month stint with Celtic starting in July 1991, pointed to the club’s record in European football as proof they’re still not a good side despite breaking the UK record after going 63 domestic games without defeat.
He told talkSPORT: “Domestically they’re so far ahead, miles ahead. But they’ve lost to Astana, who are from Kazakhstan.
“They’ve been bashed up 5-0 by PSG. OK, PSG are capable of beating any team. They’ve been beaten home and away by Bayern Munich. They’ve drawn with Rosenborg in the qualifiers.
“So it’s clear they are on a completely different level from everyone domestically but are still not a great side.
“Just look at the points total last year. It’s just so ridiculous that we can’t give Celtic too much credit.
“To justify this great run they’ve been on – well, who have they actually beaten? Beating Ross County and St Johnstone when this team’s miles ahead – it just feels this means nothing.”