The 23-year-old was heavily linked with Bayern and Barca last season, while Liverpool were also reportedly keen on the midfielder.
However, Goretzka opted for a move to the Bundesliga champions, a decision which he believes was best for his career.
When asked about Barca's interest by reporters, he said, "That was an honour, of course.
"I had several options and took a lot of time for my decision and believe that I have made the best choice with Bayern.
"I see myself as a number eight, but I'm flexible. I'm ready to play in different positions.
"I have a very positive impression of [head coach Niko] Kovac. Everything else will come over the next few days."