The Friuli lost 6-5 on penalties to their Portuguese opponents to miss out on the competition proper and Guidolin said afterwards that he would "go home, rest and consider my future".
He then asked to meet with club owner Gianpaolo Pozzo after training on Wednesday morning, but the latter confirmed there will be no change as his side bid for success in Serie A and the Europa League.
"Guidolin is and will still be Udinese's coach," Pozzo told Udinese Channel.
"His bitterness and the words he spoke on Tuesday came from the fact he is a very sensitive man, he always gives 200% in what he does and always manages to transmit it to the squad.
"Those words come from the disappointment we all felt on Wednesday night.
"Needless to say we totally believe in him: he is loved by the Friulian people and he feels this love. He loves Udine, its people, Udinese.
"He has a long contract with us and he feels happy to continue working for our club.
"I talked to him on Wednesday morning and, even though I can understand his disappointment, I made him understand how much we believe in him and that, although we feel sorry for how it went against Sporting Braga, it's all over now.
"Now we turn a new page, all together."