Bayern Munich coach Pep Guardiola and midfielder Thiago Alcantara will return to the Camp Nou for the first time in the Champions League semifinals.
Coach Guardiola left Barcelona in 2012, with Thiago following him to the Bundesliga a year later.
He said he was looking forward to going back to the club that was "our life," with the first leg being played in Catalonia.
"It is indeed special for me, but also Thiago and for my staff. Barcelona was our life," Guardiola told his prematch news conference ahead of the weekend's Bundesliga match against Hertha Berlin.
"There's nothing bad I can say about my old club. I have great respect for them and I will never forget this match and this experience.
"I was successful there, but I am happy to be at Munich now. But believe me, Barcelona are the strongest team."
He praised Barca coach Luis Enrique, a former teammate, saying he had "great qualities" and added: "He's a great guy, and I am looking forward to meeting up with him."
But he was swift to warn his players that they could not afford the sort of sluggish performance that saw them lose the first leg of the quarterfinal 3-1 to Porto before salvaging the situation with a 6-1 win in Munich.
"Should we play like in the first eight minutes at Porto [when they conceded two goals], we needn't bother showing up at all," he said.
Guardiola won three La Liga titles at Barcelona, as well as lifting the Champions League with them in 2009 and 2011.
He said: "They have a different coach, but they still play like they used to. When they are in attack all the time, they don't need to defend that much."
Falei! pic.twitter.com/c7s9Wa0qPP
- Thiago Alcantara (@Thiago6) April 24, 2015
Thiago said: "We will give it our all to advance and play for the European crown in Berlin," posting a picture on Twitter of himself and his brother Rafinha -- who is still at Barcelona -- chatting on the phone.
The two sides have met eight times in European competition, with Bayern winning their most recent meeting, in the 2013 Champions League semifinal, 7-0 on aggregate.
And Bayern sporting director Matthias Sammer said: "Only football can write those stories. I am really looking forward to it. I think the chances are 50-50."
On Twitter, Bayern keeper Manuel Neuer said his side had been given "a hammer draw," while skipper Philipp Lahm said playing the return leg at the Allianz Arena "could be an advantage."
Natürlich ein Hammerlos. Aber mit Barcelona haben wir vor 2 Jahren im CL-Halbfinale gute Erfahrungen gemacht. #FCBFCB pic.twitter.com/geJI5mGcm1
- Manuel Neuer (@Manuel_Neuer) April 24, 2015
That reaction was echoed by honorary president Franz Beckenbauer, who told Sky: "It might be a small advantage that Bayern play away from home first.
"[Lionel] Messi, Neymar and [Luis] Suarez are pretty much the best there is in attack," he said.