Miroslav Klose claims the years he spent playing under new Manchester United manager Louis van Gaal were the hardest of his career.
The 36-year-old - Germany's all-time leading goalscorer with 71 goals - left Bayern Munich in 2011 after struggling to satisfy the Dutchman.
He played 60 games while Van Gaal was in charge of Bayern, but scored only 12 goals.
"It was a tough time, particularly working with Van Gaal," Klose said.
"I didn't feel free. It was very difficult for me to fulfil his expectations. He was asking me to make runs I just couldn't see.
"I gave it all I could, but sometimes it just wasn't enough."