Furious AC Milan vice-president Adriano Galliani has slammed Francesco Guidolin's side for damaging Italy's Euro coefficient ranking, with the Italians having plummeted to 12th position below the likes of Cyprus and Israel.
Udinese rested star striker Antonio Di Natale for their trip to Parkhead when they fielded a youthful side.
And Galliani blasted: "This is why Italy are ranked below Cyprus. Despite the three victories from Inter, AC Milan and Napoli we even lag behind Cyprus.
"Do you know why? It's because some clubs show a lack of interest in the Europa League. We even set aside a contribution payment to motivate them but when the games arrive they rotate their squads."
Despite selling top names like Alexis Sanchez to Barcelona and Gokham Inler to Napoli, Udinese continued their fine start to the season with a 2-0 victory over Bologna yesterday.
And coach Guidolin admitted his delight at his side's continued fine form. He said: "It really is very satisfying even although I get angry when I hear people in the stands comparing us with Barcelona."
Meanwhile Celtic's next opponents in the Europa League, Rennes, lost 2-0 to defending champions Lille in the French League.