In an exclusive interview with bundesliga.com, the 29-year-old - whose last senior international cap came in Brazil four years ago - discusses Bayern's latest domestic triumph, playing in his preferred defensive midfield role, working under Heynckes and this summer's showcase event in Russia...
Watch: Javi Martinez and the keys to Bayern's successful title defence
bundesliga.com: Javi Martinez, how does it feel to win the Bundesliga title for the sixth time?
Javi Martinez: The title win is really very special, and shows the quality we have at the club and in this team. Titles are always a team effort, but we'll keep going right until the end of the season.
bundesliga.com: How important is the Bundesliga title for a club like Bayern?
Martinez: The Bundesliga title is very important. It's the foundation for a lot and the motivation to go on and achieve more. And it's exactly what's required at a club like Bayern. Winning the Bundesliga is a marathon that demands absolutely everything from everyone in the team. Like I said, it's a team effort.
bundesliga.com: Bayern won the treble in 2013. Is 2018 comparable to 2013? You've even got the same coach...
Martinez: (Laughs) That's true, but we shouldn't be thinking about the similarities. To be successful, it's better to take things one step at a time and move from one objective to the other.
bundesliga.com: A lot has been said about the importance of Jupp Heynckes after Bayern clinched their sixth successive Bundesliga title...
Martinez: We're all delighted that he decided to come out of retirement. He's very important for the club and the team. He knows the team and the club. It was the right decision to bring him back.
bundesliga.com: How happy are you personally that Heynckes came back? You're a key player for him and have been reinstated to defensive midfield after playing in defence under Pep Guardiola and Carlo Ancelotti.
Martinez: (Laughs) I never thought he'd return to football - not an active role, anyway. I thought he was enjoying life on his farm - without having to work with us players and have a constant stream of matches to deal with.
bundesliga.com: And your return to midfield?
Martinez: It feels good to be back in midfield. It's the position I've always enjoyed playing in. You also have a lot of responsibilities in central defence, but I've been a number 6 since very early on in my career. That's where I think I can best help the team.
bundesliga.com: Heynckes is a particularly special coach for you, then?
Martinez: A lot changed in my life when I moved to Munich in 2012. Actually, pretty much everything. I could sense almost immediately that the coach had faith in me, and that made everything a lot easier. I can only thank him - and the club.
bundesliga.com: Let's talk about the World Cup and the tournament favourites...
Martinez: (Laughs) Are you wanting to talk about Germany?
bundesliga.com: Good idea.
Martinez: Germany are the holders, so they're automatically among the favourites. On top of that, the team is also brimming with top players. A lot of them play for Bayern (laughs). Germany are a massive challenge for anyone.
bundesliga.com: If we're talking about favourites, we have to include Spain in the debate. How do you rate the team and are you hopeful of going to the finals?
Martinez: There's no doubt Spain are one of the favourites to win the title. Speaking purely as a fan, the way they played in qualification was really impressive.
bundesliga.com: What are your chances of going to the World Cup?
Martinez: I can only say that I'll fight for my chance to go to the World Cup with Spain. It's difficult to get into the team because there are so many top players, but I was obviously disappointed not to be called up for the most recent friendlies. Like I said, though: I'll never give up. I'll give everything to be there.
Javi Martinez was speaking to Oliver Trust