John Hartson has tempered expectations for Celtic’s Europa League campaign ahead of their clash with Celta Vigo.

That’s as if fans needed their expectations checked after a dismal start to their European campaign saw Martin O’Neill’s men defeated comfortably by both Ferencvaros and Benfica.

In desperate need of points on the board this Thursday, they face a Celta Vigo side sitting eighth in La Liga under highly-rated manager Claudio Giraldez. It doesn’t get any easier.

And when Hartson looks back on the O’Neill sides of old — of which he was a part — he can’t help but notice a stark drop-off in standards and expectations.

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John Hartson on Celtic vs Celta Vigo: ‘It’s getting harder’

Hartson said speaking to the Scottish Sun: “It’s a big game. Losing the first home game to Ferencvaros wasn’t great, and we’ve been thumped by Benfica. Celta Vigo will be tough opposition again. 

“If we’re being honest about it, Celtic maybe aren’t as good a side as they have been in the last two or three years. They’re certainly not as free-flowing as a team.

“They did exceptionally well to win their last seven games to win the league last season, but you don’t want to be putting the fans through that every year.

“But it’s definitely getting harder and harder in Europe. Back in my day, we had a strong squad to be able to cope with the top teams. Look right through our squad, and it had internationals in every position. 

“But at this moment in time Celtic just aren’t looked at as a brilliant European side. I do think they’re capable of winning domestically. But in the Europa League, the expectation isn’t very high.

“There will be a full house on Thursday night and there will  be a wonderful atmosphere, like there always is. I just think the general feeling is that they’re not as strong as they have been. 

“It’s turning out to be a really hard European campaign, but that’s not to say the team can’t produce a big performance. I hope they can get a result this week, which gets it going for them in Europe this season.”