Martin O'Neill gave a blunt and brutal assessment of Celtic's issues after their Europa League thrashing by Stuttgart, slamming a fan protest, explaining how a Premier League switch could boost their European prospects and defending Kasper Schmeichel.
O'Neill's side are all but out of their knockout play-off with Stuttgart after a 4-1 humbling in the first leg at Celtic Park.
The game was halted inside the opening seconds when fans threw balls onto the pitch to highlight their frustration with the club's board, while goalkeeper Schmeichel was later booed after making errors for Stuttgart goals.
Speaking afterwards to TNT Sports, O'Neill described his team as "masters of our downfall" but also pointed to problems beyond the pitch, including Celtic's limitations in the transfer market, saying: "Eventually, if the SPL [Scottish Premiership] belonged to the Premier League, I don't think we'd have a problem."
On the prospect of Celtic pulling off a turnaround in the second leg, he conceded: "At some stage, Celtic will become a top-quality European team. That's in the future. But at this minute, our battles are elsewhere."
After a rousing rendition of You'll Never Walk Alone and with a big atmosphere generated at kick-off, Celtic supporters halted the game within seconds of the first whistle.
It took around four minutes to clear up all the toy balls which had been thrown onto the pitch in protest at the club's owners.
O'Neill didn't hide his frustration at how the incident had hampered his side, when asked about it by TNT Sports after the game.
"Anybody who thinks that's a good idea needs their heads examining," he said. "There's no question about it. It sends out totally the wrong message.
"We are playing against Stuttgart. The game is hard enough.
"The problem is, way back, some years ago, this was an incredibly intimidating place to come to. Incredibly difficult. I've managed here when sides like Juventus were scared stiff of coming here. Where top class sides were scared stiff.
"That sort of thing does not help at all.
"There have been battles going on [between fans and the board] but that doesn't help. All it does do, Stuttgart come to this wonderful football club and find a lot of in-fighting going on and things being thrown onto the pitch... it doesn't make any great sense to me.
"If I'm a Stuttgart player, I'm thinking I'm pretty happy in this environment, if that's the case."
Celtic haven't won a European knockout game since O'Neill oversaw a victory against Barcelona in 2004. Asked about the gulf in quality between Celtic and European sides, O'Neill suggested Scottish clubs may have to eventually combine with the Premier League for financial reasons.
"It's very difficult for Scottish teams [in Europe]," he explained. "There's no money, in that sense. You're talking about Premier League teams, Bundesliga teams buying players for £40m-£50m and them not even playing, not getting into the side.
"Players in the Premier League in the last couple of seasons have cost £70m or £80m and are transferred for £40m about three months later. So it's ridiculous.
"We have to try to compete with that. At some stage or another we have to compete with that. That's the difficulty of it.
"You're trying to get players in at low cost because there's no money. Eventually, if the SPL [Scottish Premiership] belonged to the Premier League, I don't think we'd have a problem."
O'Neill told TNT Sports he didn't hear the boos or ironic cheers from Celtic supporters directed at Schmeichel in the second half but defended his goalkeeper and the contributions he's made to the club.
"Kasper Schmeichel has made some great saves since I've been at the football club," he said.
"There was the game against Feyenoord, where he pulls off a great save there otherwise we might not be playing tonight.
"This is a collective. There's no doubt at all about that."
Summing up the performance, O'Neill said: "It's a tough evening for us, obviously, 4-1 looks pretty poor.
"We were masters of our own downfall in many aspects. We conceded some very poor goals.
"I felt at 1-1 we were well and truly in the game, even at half-time, 2-1 down.
"It was a tough evening."
