Having clinched a 1-0 win over Roberto Mancini's entourage in the first leg, Brendan Rodgers' men would be aiming to confirm their progress to the Round of 16.
"The whole Celtic team were good and played well, in the second half we improved and managed to stop them and it was a shame to lose the game towards the end".
"We know Celtic is a good team with good players, a good manager and we knew it was going to be a hard game".
"We know they are good players and they have quality, but so do we and we showed that last week".
Speaking at Celtic's hotel in St Petersburg yesterday, Rodgers said: "It would be a huge achievement for us". We knew Celtic are a good team with good players, a good manager and we knew it was going to be a hard game.
"European football is notoriously very hard for ourselves but I think we showed in the first leg how well we can play".
A small section of the Krestovsky Stadium will be closed tonight because of a Uefa sanction for racist behaviour from some fans when they played Vardar Skopje earlier in the Europa League.
"But you have to be able to play quality football and to do that you have to stay calm and retain your emotions, no matter how the game goes".
"Our belief has always been there".
The Russian also stated that the whole Celtic team played well in the first leg as he insisted that it was a "shame" for Zenit to concede late on in the game.
"They will be expected to go through over the two legs, so my mindset hasn't changed".
"If we can get to a similar level then we have a great chance".
"In the return match we must score".
"But at the same time we are a good team, the only problem is we didn't play for two months".
Rodgers said: "Zenit are predominantly a counter-attacking team and they have scored a lot of goals in their season so far, and they have players of quality".