While Manchester City face Liverpool in an all-Premier League tie and holders Real Madrid take on Juventus in a repeat of last year's Champions League final, Bayern arguably have an easier task.
But Sevilla knocked out Manchester United against the odds in the last round, Vincenzo Montella's men winning 2-1 at Old Trafford thanks to a brace from Wissam Ben Yedder.
And Heynckes - who won the Champions League with Bayern in 2013 at the end of his third spell in charge - will not be taking progression to the semi-finals for granted.
"They are a really good team," Heynckes said of Sevilla at a news conference. "If you watched them play against United, even after the 1-0 lead they noticed that United needed two goals and they played really good football. We can't afford to celebrate already.
"Of course, Real Madrid, Barcelona, Manchester City are playing very well, Liverpool are playing well, but we had five English teams [in the round of 16] and we were talking about the best league in the world and three of them are gone, so we must take these guys seriously.
"The team was not euphoric [at the draw], they reacted very calmly, as though they just had a beer.
"The video analysts have to filter the strengths and weakness of the opponents and I'll watch three or four opposition videos. We'll have the same approach to this game but I know Spanish football very well.
"I experienced Sevilla when [Diego] Maradona was there. It was a novelty at the time, he never warmed up, he just juggled the ball in the corridor. I know the atmosphere, I know what to expect there, we have to be really careful if we want to win this quarter-final."
Juventus have lost two of the last three Champions League finals, but Heynckes feels Massimiliano Allegri's side have a chance of claiming revenge against Madrid, who beat them in Cardiff last year.
"You should never underestimate Juve - we saw that against Tottenham," Heynckes said.
"They are a team that maybe because of [Leonardo] Bonucci [who was sold to AC Milan] aren't as stable defensively, but they are still competitive, they are experienced, have a top coach, [he has] been in the Champions League final twice so that won't be easy for Real Madrid.
"Liverpool-City is the highlight, for me. It's an open tie. The way Liverpool have been playing the past few weeks is really impressive, the offensive power they show on the pitch, the distance they cover, I have been very impressed with them. City play beautiful football but it's the quarter-final of the Champions League – different rules apply."
Bayern won the second leg of their last-16 tie against Besiktas 3-1 despite having a huge 5-0 advantage from the first encounter in Munich, much to Heynckes' pleasure.
"I think it's really positive how my team responded on Wednesday," he added.
"Both City and Liverpool won the first games very easily, they lost or drew [in the second legs], but we won. That's very positive. My players were very decisive so I really like that a lot."