With both teams on the verge of the Champions League final, they must be prepared for a Spanish backlash this week.
So much has been written about last week’s overwhelming victories by German clubs over their Spanish counterparts in the Champions League semi-finals that neutral observers could be forgiven for thinking Borussia Dortmund and Bayern Munich only had to turn up for the second leg to qualify.
But foregone conclusions are not something the Germans consider — and both Dortmund and Bayern will be only too aware of the pitfalls of complacency.
In fact, despite the impressive scorelines — 4-1 for Dortmund against Real Madrid and a crushing 4-0 for Bayern over Barcelona — there is no cause for German celebration until at least another 90 minutes’ football has been played out.
First up is Real v Borussia on Tuesday night, and although Dortmund have the psychological advantage of having taken four points off the Spaniards in the group matches earlier in the competition, one simple matter has been overlooked in all the hype about their first leg victory.
That concerns the away goal Real mustered in the Ruhr, which could yet be their lifeline to qualification for the final.
With their backs to the wall and playing for coach Jose Mourinho to hold on to his job as much as for personal glory, Real are perfectly capable of knocking in three goals without reply in front of their own fanatical crowd, who will doubtless be baying for blood from the kick-off.
Much depends on the fitness, or otherwise, of Portuguese star Cristiano Ronaldo.
No-one is suggesting Real are a one-man team but Ronaldo is vital to the way they function and the thigh injury he picked up in Dortmund could yet restrict him to a cameo role in the second leg.
Admittedly, Real beat Atletico 2-1 in the Madrid derby without him and a host of first-team regulars, rested with Tuesday in view but the fears that he may not be fully fit are not being voiced in the Spanish capital.
Angel Di Maria, who scored the winner after his free kick was turned into his own net by Juanfran for an equaliser, commented: “Winning today gives us extra motivation for Tuesday, which we hope will have the best possible outcome.”
Dortmund also won 2-1 away on Saturday, at near neighbours Fortuna Duesseldorf, but rested 10 of the side that beat Real, including four-goal hero Robert Lewandowski for all but the last 20 minutes.
Meanwhile, Bayern, who also made 10 changes from the side which slaughtered Barcelona, managed a 1-0 win over Freiburg to break the record number of points for a Bundesliga season.
Barca, of course, have already shown themselves capable of putting four without reply past crack European opponents, as they did in the quarter-final against AC Milan to overturn a 2-0 deficit from the first leg.
And, even if the mercurial Lionel Messi is less than fully fit, it is generally thought Barca cannot play so poorly, or look so slack at the back as they did in Munich.
Messi, however, did come to their rescue in the 2-2 draw at Athletic Bilbao, coming on as a second half substitute to score a brilliant individual goal and set up Alexis Sanchez for a second goal.
But even if they were to score four, all but their most diehard fan would have to fancy Bayern to nick an away goal at the Nou Camp, especially considering their comprehensive demolition of another of the continent’s dominant sides, Juventus, who they beat 2-0 both home and away to advance to the last four.
There was really little indication to be gleaned from the weekend action as to what might be coming up as all four protagonists rested key players ahead of the crucial midweek matches.
But with form and first leg scores taken into account, London’s Wembley Stadium, venue for the final on May 25, can probably prepare for the arrival of German supporters, as Bayern and Borussia attempt to win European club football’s leading competition.