Krystian Bielik has left Arsenal and completed his move to Derby County.
The Rams have confirmed a deal to take Bielik to the Championship club, which could eventually be worth around £10million.
Bielik had been with Arsenal since 2015 after they paid Legia Warsaw £2.4m to sign him.
The 21-year-old helped get Charlton promoted to the Championship last season and is now looking forward to testing himself further in the second tier of English football.
He told Derby's official website: “That was a good time to leave. They didn’t see me as the future anymore and the manager had different plans as well.
“It was sad when I left the training ground but I spent four and a half years at Arsenal. I joined them at 17 so I was only a kid but I leave there as a man.
“I am a 21-year-old man now and I know what I want. That is to play first team football and that’s what I need.
“I’m here to help my teammates and here to do another step in my career. I promise I am going to do my best in every training session and in every game.
Arsenal meanwhile are hoping to make further additions to their squad before Thursday's transfer deadline, with Celtic's Kieran Tierney on their radar.
