Pep Guardiola is not the only connection between Bayern Munich and Barcelona, who meet in their Champions League semi-final, first leg at the Allianz Arena on Tuesday.
Both teams are dominating their leagues to an almost embarrassing extent, have won the Champions League four times apiece, share an acrimonious rivalry with Real Madrid, and owe part of their success to the flamboyant Dutchman Louis van Gaal.
Both have also been in two Champions League finals in the last four years, though the Catalans won both of theirs and the Bavarians came out losers on each occasion.
Barcelona are 13 points clear at the top of La Liga, yet could be considered underdogs against a rampant Bayern, who wrapped up the Bundesliga two weeks ago and won two games by 6-1 margins this week even when resting their top players.
"The players are just enjoying their football, and our attitude is superb. Every man was totally motivated, we put together some very fluid moves, we showed great discipline, and we created outstanding goals," said coach Jupp Heynckes after Saturday's 6-1 win at Hanover 96.
"Once again, the players have proved we don't have a B-team, we only have an A team."
Bayern's dominance has caused some disquiet in the Bundesliga, which often proclaims itself to be Europe's most open league.
"There's a big difference in performance levels in the league," club president Uli Hoeness told Kicker last week. "We can't be comfortable with that. We have to analyse why this is the case."
Barcelona's superiority in La Liga has led to suggestions from Madrid media that it has become a formality for them and they will not even celebrate winning it.
"It appears there are people who want to make out that the league doesn't count for anything, but that's not the case, it's a very important title," said midfielder Cesc Fabregas. "We have worked very hard."
"If we do eventually win the league, there is no doubt that there is great merit in taking four titles in five seasons," stand-in coach Jordi Roura said. "It's a very difficult championship."
Bayern believe their playing style and policy of giving priority to players raised locally makes them similar to Barcelona and that it was only natural that Guardiola, who quit the Nou Camp last season, should continue his career at the Allianz Arena from next season.
Hoeness revealed recently that Bayern had been involved in talks with Guardiola long before he agreed to coach them in January.
"I had the impression from the beginning that Bayern are a club who are quite close to Barcelona in footballing attitude, so it was not that difficult for us to convince him," Hoeness told World Soccer magazine.
Van Gaal Claim
Then there is the Van Gaal connection. The Dutchman left Bayern when he was sacked two years ago, but has a legitimate claim to be the architect of the current side.
It was under Van Gaal that Bayern began to press the opposition in their own half and play attacking, possession football, a style that makes them such formidable opposition.
Van Gaal also put together the dreaded Arjen Robben-Frank Ribery parternship just behind the Bayern centre forward.
Van Gaal left Barcelona in similarly unhappy circumstances in 2000, yet he also revived the Catalan club, winning successive La Liga titles to end a four-year drought and took the decision to make Guardiola captain.
Matches between Bayern - who will be without suspended striker Mario Mandzukic and injured midfielder Toni Kroos - and Barcelona have been surprisingly rare, with just six previous meetings.
The last, a Champions League quarter-final four years ago, came when Juergen Klinsmann's reign at Bayern was in its death throes and saw a 4-0 Barca rout in the first leg with all goals coming in a memorable first half.
"I remember that game well and I don't really like to think about it, because it was quite painful to watch," said Bayern chief executive Karl-Heinz Rummenigge.
"However, it's a wonderful opportunity to show that we have improved a lot since then."
Barcelona will be without injured defenders Javier Mascherano and Carles Puyol, leaving Roura with a headache in deciding who will partner Gerard Pique at the centre of the defence.
Bayern Munich: 1-Manuel Neuer; 2-Philipp Lahm, 5-Daniel van Buyten, 4-Dante, 27-David Alaba; 31-Bastian Schweinsteiger, 8-Javi Martinez; 25-Thomas Mueller, 7-Franck Ribery, 10-Arjen Robben; 33-Mario Gomez
Barcelona: 1-Victor Valdes; 2-Daniel Alves, 3-Gerard Pique, 22-Eric Abidal, 18-Jordi Alba; 6-Xavi, 16-Sergio Busquets, 8-Andres Iniesta; 9-Alexis Sanchez, 10-Lionel Messi, 17-Pedro.