At the back, Atletico goalkeeper Thibaut Courtois has only conceded two goals at home this season. On Wednesday, he'll be making his Champions League debut.
"I have wanted to play in the Champions League since I was a kid and I'm really excited about doing it with Atletico," Courtois said. "We have to give it our all."
Zenit is in second place in the Russian league, and beat Terek Grozny 2-0 over the weekend.
"We are playing better and better every match," Zenit coach Luciano Spalletti said.
Zenit will be without midfielder Roman Shirokov, who injured his groin in the first half against Terek. Defender Alexander Anyukov will also miss the match.
Austria Vienna, which is making its Champions League debut, is the first Austrian team to reach the group stage since Rapid Vienna in 2005.
"(We) must play perfect football to stage an upset," Austria Vienna coach Nenad Bjelica said. "Porto has a solid defense, is technically strong and has a great player for each position."
Porto, the Portuguese champion for the past three years, is off to a perfect start in the domestic campaign and is already leading the Portuguese league by two points after four games.