Brendan Rodgers says Celtic are under "no illusions" they are in for a tough test against Borussia Dortmund in front of the 'Yellow Wall' in the Champions League. (More Football News)
Celtic got off to a flying start in the last round, brushing aside Slovan Bratislava 5-1 last month to win their Champions League opener for the first time, and sit second in the table behind Bayern Munich.
Having also won their final group-stage match last season, Rodgers' side are looking to win three consecutive matches in the competition for the first time since 1976.
But coming up against last season's runners-up, who began their campaign with a 3-0 victory over Club Brugge, is a different prospect for the Scottish champions.
Asked if this was the "acid test" for his side, Rodgers said: "I think this level is about as much about the head as it is about the skill. I don't doubt that with this team.
"I think we arrive in a great place. I am very relaxed and focused that we can get a result that builds on the first result."
Celtic have started the season in fine form and top the Scottish Premiership having won all six of their games, scoring 20 goals while conceding none.
Despite their strong start, Rodgers is looking back to pre-season to draw inspiration, after beating Manchester City and Chelsea in friendlies, scoring four times past both in back-to-back matches.
"I track it back to pre-season," he said. "The games that we played there, played some big teams and how we wanted to play at this level.
"We got off to a very good start in the last round, so we come here to a stadium very much like Celtic Park in that they breathe football, and we're very excited by the challenge.
"We are under no illusions that we are up against a team who are challenging at the very top of elite football, but for us, I've always said, whether domestically or away in this competition, it is about making us very difficult to play against with and without the ball.
"Offensively, Dortmund are very good. They lost some players in the summer, but I look at the team, and they have some fantastic players in that middle-to-top area, so will put you on the back foot at times.
"It is a top side with top players, and we have to be right on it to get a good performance and result."
