Bayern are favourites to progress to the quarter-finals after a goalless draw in the opening meeting in Lviv three weeks ago.
Last season, Pep Guardiola's side reached the semi-finals and were well in the tie after a 1-0 loss at Real Madrid in the first leg, before the Spanish giants tore Bayern apart 4-0 in the return at the Allianz Arena.
The nature of that defeat caused some to question Guardiola's tactics, but Lahm has defended his coach's philosophy.
"This discussion is unnecessary," he told Perform. "In the 17 games before, plus the previous season, everyone hailed our style of play.
"We conceded four goals in the first leg [first 17 league games] of the season. This system is risky when not all of the players do what they are supposed to do.
"If more of players do not fulfil their positions, then it looks like against Wolfsburg [when Bayern lost 4-1].
"Then we get problems. If it works - and it worked for over a year and a half very well - this system is top."
Lahm conceded that the heavy defeat to Real last season was a painful lesson, but says his team-mates are fully focused on putting those memories behind them this time around.
"Defeats are also part of our game as everyone knows especially everyone who works for this club," he said.
"It was not a bitter elimination because it was not early in the competition or a bitter elimination because it was close. It was a bitter elimination because it was a defeat in a semi-final.
"Of course it annoys you because we wanted to play the finals, But this year we already have the next chance to accomplish that.
"We won the double and seven players from our team won the World Cup later. So they won a special triple. It was a very good season again and now we are trying to charge again."
