Bastian Schweinsteiger's second-half equaliser at Old Trafford last week means United have to score at Bayern's fortress on Wednesday night to progress to the Champions League semi-finals.
But Guardiola is not bracing himself for an attacking onslaught from the reigning Premier League champions.
The Spaniard - and Bayern - have found life tough against English teams on a few occasions recently due to the tactics employed by their opponents.
Two years ago Chelsea edged into the final with a 3-2 aggregate win that was characterised by stubborn defending and fast counter-attacks.
It was the same story in Bavaria the following month when the Blues defended for their lives and beat Bayern in their own stadium on penalties to lift the trophy for the first time.
"They are so defensive," the Bayern coach said when asked about his experience of playing English teams.
"They use the counter-attack very well.
"It's always difficult when one team stays there just to defend, and waits until you make a mistake.
"Obviously when they play at home they attack a little bit more but when they play away they defend.
"Maybe (United manager) David Moyes thinks another thing, but I think they are going to wait back with eight or nine players in the box, await our mistake and wait for a free-kick or a corner to punish us."
Many expected Bayern to give United a real hiding at Old Trafford, but Nemanja Vidic's header means United's slim hopes of reaching Lisbon are still alive.
Wayne Rooney was key to last week's draw as he put in another typically combative display to trouble the German side's defence.
The England striker was hobbling towards the end of the first leg with a toe injury which caused him to miss United's 4-0 win over Newcastle on Saturday.
Rooney took part in United's final training session before the second leg though and Guardiola is so sure he will play that he is willing to stake a stein of Munich's finest beer on it.
"I bet you a big glass of beer," said Guardiola, who beat United in two Champions League finals with Barcelona.
"Rooney is going to play. He is one of the best players I have ever seen.
"(Moyes) has a lot of problems so Rooney will play."
Anyone at Guardiola's pre-match press conference would have assumed that it was the Bayern coach and not his opposite number who had problems though.
The near half-hour session was full of questions about whether Bayern had lost their confidence, their rhythm and belief.
That will come as a surprise to most as Bayern won the Bundesliga two weeks ago with a record seven matches to spare while United are only seventh in the Premier League.
The reason those questions arose was because Bayern's 53-match unbeaten streak in the league came to an end on Saturday when they lost to Bundesliga minnows FC Augsburg.
Guardiola sought to play down the defeat, in which he fielded three debutants.
"I am sad we lost, but the game against United here has been our target for the last couple of weeks," Guardiola said.
"They are fighting to qualify for the Europa League next season, and we have already won the Bundesliga."
Guardiola has started to show signs that he is feeling the pressure though.
At Old Trafford he snapped at one reporter in his post-match press conference and on Tuesday he admitted that if he does not win the treble like his predecessor Jupp Heynckes did last year, he will be disappointed.
"If we are not in the Champions League semi-finals it would be a huge mistake for the new manager. If we are not in the final this club cannot deal with that," the 43-year-old.
"They won the treble last season and I have got to be in that situation. If I don't, then it's not so good."
Guardiola said he only had 14 first-team players to choose from for the match.
Xherdan Shaqiri, Thiago Alcantara, Diego Contento, Tom Starke, Lukas Raeder and Holger Badstuber are injured while Schweinsteiger and Javi Martinez are suspended after being cautioned in the first leg.