CELTIC may well have dropped down a level when they went from the Champions League group stages to the knockout rounds of the Europa League after finishing third in their section back in December.

The challenge they now face progressing in the inferior of Europe’s two club competitions, however, is no less daunting or demanding.

Zenit St Petersburg, who they will take on in the first leg of their last 32 double header at Parkhead this evening, might not, for the time being at least, operate in the same stratosphere as the likes of Barcelona, Bayern Munich, Paris Saint-Germain and Manchester City.

The lavishly-assembled Russian side, however, harbour ambitions of competing alongside the continent’s elite, like many still involved in this tournament, and will not be easily overcome by the Scottish champions.

Brendan Rodgers had no hesitation declaring Zenit, who have had billions of roubles pumped into them by Gazprom since the multinational energy provider bought a controlling stake in the St Petersburg club back in 2005, favourites to go through as he looked ahead to the game yesterday.

“I never say that lightly,” he said. “I always think we are Celtic. I’m in my dream job, but I’m also a realist. When you look at their investment and the level of player they have they will expect to go through.”

Rodgers is certainly not ruling out Celtic’s chances of recording what would, discounting qualifying games, be their first home win in either the Europa League or Champions League in 11 outings, since a 2-1 over Astra Giugiu back in 2014, tonight.

Yet, he was at pains to point out that it is becoming increasingly unrealistic to expect the Glasgow club to compete with clubs from larger and richer leagues in Europe due to the ever-widening gulf in finances.

“It’s very difficult,” he said. “You see the level of opponent in there. It tells you the difficulty. What we have to do year on year is try and somehow bridge the gap, but it will always be difficult for us.

“We will see if we can get a result. But I think you get to the last 32 and they are always going to be tough games. There are teams that are winning their group stages and qualification for the Europa League. There are teams coming out of Champions League and they are always going to be tough games.”

The presence of Aleksandr Kokorin, the Russia striker cum winger, Leanardo Paredes, the Argentinian central midfielder who cost a cool €27 million in the summer, and Branislav Ivanovic, the former Chelsea player who looks set to recover from an eye injury and feature, in the Zenit side tonight underlines the magnitude of the task awaiting Celtic.

“Kokorin looks a talent,” said Rodgers. “Playing off the left side, he is a finisher. Paredes, the playmaker, is a very good footballer who sits at the bottom of their midfield and makes the passes. They have some very good players.

“They are a very good team. If you look at how they play, they are what you would consider to be a top European team with speed, power, technique and ability. They obviously have all of that.”

Could the fact that Roberto Mancini’s side haven’t played a competitive fixture in over two months due to the extended winter shutdown in Russia mean they aren’t at their best and help Celtic record a sweet triumph?

“It depends,” said Rodgers. “It just depends what way you view it. You could look at it and say it makes them fresher. The break could maybe freshen them and revitalise them and then they go again.

“We played against them when I was at Liverpool and went out on away goals (in the Europa League last 32 in 2013). It was a similar time. We played them around about February time. We lost the away leg and won the home leg 3-1. They were pretty fit then.”

Celtic haven’t, despite their fine 3-0 win over Anderlecht away in the Champions League group stages back in September, scaled the same heights they achieved last season and go into the Zenit game on the back of a defeat to Kilmarnock and a narrow win over Partick Thistle where their frailties at the back were once again exposed.

Yet, with the majority of the 60,000-capacity crowd firmly behind them Rodgers is hoping they can avoid the costly defensive errors which have become a feature of their play in recent months and produce the kind of rousing performance they did against City last season and Bayern this term.

“It’s what we wanted to do, qualify for the next stage of Europe,” he said. “It is an exciting challenge. It’s just about having the confidence and belief to play at this level. As long as we show that belief and confidence I can’t ask for any more.

“The atmosphere and everything around these games inspires the players and we have seen that in a number of games. That is something that is incredible for us. That energy gives us a real chance and a real hope.”