The two teams lock horns at Parkhead on Thursday night for the first leg of their last-32 tie after the Hoops finished third in Group B of the Champions League.
Zenit, meanwhile, topped their Europa League group and Davies believes that the Russians are a high-calibre outfit, both in terms of individual players and as a team.
"What's important to acknowledge is the level of the opponent we're about to face," Davies told BBC Sport on Tuesday.
"Having analysed them and watched them for a few months now, we know they are individually and collectively a top team, a Champions League-level team with quality. We have to recognise that, respect that and be prepared for that.
"With the quality they have, they're good in possession but also good on the counter-attack and can be a threat on set plays. Top teams can do all three of those and they have shown they're just that in the games I've seen.
"They were the top scorers in the Europa League with 17 goals in six games, so they're scoring nearly three goals a game and conceding less than one on average. These numbers tell you a story as well.
"We respect them, but we also see it as an opportunity and we're going to hopefully take a lot of positivity and energy into the game and see what happens."
Zenit, who are managed by former Manchester City boss Roberto Mancini, won five out of six games in the Europa League group stages and are the tournament's top scorers.