Toni Kroos says he "rued" signing a contract extension at Bayern Munich in 2010 after returning from a loan spell and believes he went underappreciated during his early years at the club.
He signed a new deal on his return to the Allianz Arena and went on to establish himself as pivotal member of the team that won the 2013 Champions League.
And in a new film documenting his life and career, Kroos says he often felt undervalued and underappreciated during his early years at Bayern.
"I was often told how great I was and how I was doing everything right,” said Kroos. “Still I did not play. I was convinced I deserved more.
"Originally I did not want to return [from Leverkusen]. When I signed my extension, I rued it ten minutes later.
“While I signed the contract, Karl-Heinz Rummenigge commented: 'Wow, you have got a great contract now.' It was like he told me: 'So now you have to play a little better.'"
The film, titled 'Kroos' and set for release in Germany on July 4, canvasses opinion and insight from people who have been close to Kroos during his career, including officials at his former club Bayern.
Uli Hoeness, Bayern’s vocal club president said: "Toni is a great player. But there is not one player in the world who can do everything all by himself.
“A club sometimes has to make hard decisions. This decision [to let him go to Madrid] was a hard one and maybe a wrong one, no doubt."
Since signing for Real, Kroos has enjoyed a trophy-laden five seasons, winning three Champions League titles as well as the 2017 La Liga crown.
He signed a new deal at Santiago Bernabeu in May which will keep him at the club until 2023.