Arsenal defender Per Mertesacker has given a candid and revealing interview with German publication Der Spiegel discussing the various mental battles he has gone through in his career.
The 33-year-old will hang up his boots at the end of the season to become the Gunners' academy manager, and has seemingly enjoyed a great playing career at the highest level.
Although the popular figure has been on the decline in the past few years due to his age, Mertesacker has been considered a great defender of the modern game, but it hasn't always been plain sailing for the man affectionately dubbed the 'BFG' by the Arsenal faithful.
On the prospect of going out and playing games nowadays with all the pressure, he revealed, as quoted by Goal: "Some days you realise that everything is a burden, both physically and mentally.
"That it's not about fun, but you have to deliver without a doubt. Even if you are injured.
"My stomach turns as if I’m going to throw up, then I choke so much my eyes water. This isn’t supposed to sound whiny because I am obviously aware of the privileges of my life."
Mertesacker, who is the latest top level professional player to admit to psychological struggles related to the pressure of playing, went into further detail about how his anxiety manifested itself on match days and the night before.
He continued: "[ex-teammate Clemens Fritz] said he had to try everything to fall asleep in the same room as me. My right foot would tremble so much the night before the game that the duvet would rustle and it drove him mad."
"I have to go directly to the bathroom from bed. From breakfast to the bathroom. From lunch to the bathroom. At the stadium, to the bathroom again.
"Obviously you think: ah s***, hopefully nobody sees. On the other hand, I was back to normal again immediately after, just like: bam, completely there."
The 33-year-old World Cup winner also insisted his personal issues never affected his performances on the pitch, but explained that he formed a routine of turning his head into his shoulder before kick-off so his teammates and the TV cameras can’t read any anxiety in his face.