John Hartson says he'd be making himself look stupid if he didn't give Rangers credit for their Europa League run.
But he insists Celtic are still the undisputed top dogs domestically as they get set for a title party on Saturday.
Ange Postecoglou 's Hoops have won the Premiership title against all odds and will feel delighted with their season having also banked the Premier Sports Cup.
Under normal circumstances Rangers would be mourning the loss of the title but feel they have bigger fish to fry.
Gio van Bronckhorst's team have a first European final since 2008 to look forward to while they also face Hearts at Hampden in the final of the Scottish Cup.
And Hartson feels those of a Celtic persuasion are making themselves look daft if they don't give credit where it's due for their rivals' remarkable European run.
He said on Go Radio: "Whoever you support, whether it's Celtic or Rangers, you have to appreciate how well the other team does.
"Rangers have just reached the Europa League final. It's a brilliant achievement. No matter which way you want to weigh it up, to beat the teams they have beaten to get there, it's an outstanding achievement.
"If I don't say that, I make myself look stupid.
"Giovanni van Bronckhorst came out and said Ange Postecoglou has been brilliant, congratulations to Celtic for winning the league.
"Celtic have been better in the league, and Ange will want to get to where Rangers are in terms of European performances.
"They have to improve there, they've been poor in Europe in the last couple of years. Ange wants to improve and emulate what Rangers have done, getting to a European final."
