Celtic interim boss Martin O'Neill claimed that Scottish teams find it very difficult to compete with Bundesliga and Premier League sides due to the difference in their transfer budgets.

Celtic lost 4-1 to Stuttgart in the first leg of their Europa League play-off tie, leaving them with a mountain to climb if they are to reach the last 16.

It was O'Neill's second defeat in charge of Celtic in 2025-26, after losing 1-3 to Midtjylland in November, while it was his first loss at Celtic Park since a 1-3 defeat to Hibernian in April 2005.

Celtic, meanwhile, have lost four of their last six home games in major European competition (W2), as many as in their previous 13 matches combined (W6 D3 L4).

Although they outperformed Stuttgart on expected goals (2.09 xG to 1.88), O'Neill did not see their defeat as a huge surprise.

He told TNT Sports: "It's a tough evening for us. On paper, 4-1 looks pretty poor. We were masters of our own downfall in many respects, conceded some poor goals.

"At some point, Celtic will become a top quality European team. That's in the future. At this moment our battles are elsewhere. Our focus now is totally on Sunday.

"It's very difficult for Scottish teams. There's no money. You're talking about Premier League sides and Bundesliga sides buying players for £40m and them not playing."

Play was halted just 12 seconds after kick-off when Celtic fans threw tennis balls on the pitch in protests at the board.

O'Neill was far from happy about the actions of the home supporters at Celtic Park.

"Anyone who thinks that is a good idea, needs their head examined," he added.

"A way back, this was an incredibly difficult, intimidating place to come. Teams like Juventus were terrified coming here.

"That sort of thing does not help at all. What it does do, is Stuttgart find out there's a lot of infighting going on. It doesn't make sense to me. If I'm a Stuttgart player, I'm pretty happy if that's the case."