The Brazilian winger has been one of the most impressive players in the Bundesliga this season with champions Bayern Munich. Costa has spoken about life under Guardiola and how becoming a footballer wasn't his dream.
The contribution of Douglas Costa in Bayern Munich's unbeaten defence of the league championship shouldn't be understated. Signed from Shakhtar Donestk last summer for 30 million euros ($32.4 million), the 25-year-old winger has 14 scorer points (two goals, 12 assists) in 12 Bundesliga matches.
Quick, skilful and a peristent nuisance for defenders, Costa's arrival has brought an added dimension to Pep Guardiola's team. Costa's style is similar to that of Arjen Robben, often a match winner for Bayern against opponents who are tough to breakdown. But with Robben now back in the fold, the influence of Guardiola has helped Costa hold down a fluid position - left, right, or center.
As Costa explained in an interview with German broadcaster "Sport1," Guardiola's coaching is beginning to rub off on his game.
"Everyday that I can spend with Pep Guardiola is educational for me," he said. "When I'm at his side, I try to learn something new everyday.
"Pep Guardiola is the best coach in the world. The communication with him is great and there has been no problem from the first minute."
Born around 30 kilometers (18 miles) from Porto Alegre, Costa began his career at Gremio, one of the two major clubs in the Southern Brazilian city. But at 19, Costa left to join Shakhtar and become the seventh member of the club's nascent Brazilian community in January 2010.
With five goals, he helped the club to the league title in his first season. Costa went on to collect a league winner's medal five years running and win three Ukrainian Cups.
"I felt good in Ukraine," he said, "but in relation to my sporting goals and prospects compared with Bayern, I have to say, I have more in five months at Bayern than five years in Donetsk."
Signing a five-year-deal at the Allianz Arena, Costa became the fourth most expensive player in the club's history. Those exorbent figures highlight just how far Costa has come; from simply admiring the precocity of Ronaldinho, to emulating his idol by succeeding in Europe, a dream for most young professionals in Brazil, if not Costa.
"I never really had the dream to become a professional footballer," he admitted. "I only started at nine years old to play; it was actually a great passion of my father who wasn't a professional. But this inspired and pushed me on. It was a fulfillment for me and my father because now I've managed it. And we both are now very happy with what has happened."