Martin O'Neill has lauded the impact of Ange Postecoglou at Celtic - but admits he could have lifted a Treble this season.
The Australian has impressed during his debut season at Celtic Park lifting the Premier Sports Cup and putting the club on the brink of the Scottish Premiership title.
However, hopes of a Treble were dashed by Scottish Cup semi-final defeat to Rangers at Hampden.
Celtic legend O'Neill reckons that a domestic clean sweep was there for the taking as Postecoglou looked to join an exclusive club of Parkhead bosses who won it all.
The former Aston Villa and Ireland boss didn't hold it against the Australian, though, as he offered a rave review to the boss.
He told PLZ: "He's done brilliant, absolutely brilliant. He might be a bit disappointed about what happened last week (against Rangers), but it's really terrific.
"I have much time for a lot of managers, but where I found that he was particularly good was that he came in, was not that well known and had a tough old start, but had to stick to his beliefs.
"He felt he can get this right and with a bit of time something will change for me. To his eternal credit he did exactly that and got it going.
"There might be some moment where he thinks that the tide turned for him, I don't know you would have to speak to him.
"He has been marvellous. There treble was there for a moment or two, but it didn't happen.
"But if you were to ask any Celtic fan about winning the league (they would say) it's the top priority."
