Arsenal legend Ray Parlour has raised concerns that attacking midfielder Alexis Sanchez could decide to leave the club in the summer.
The Chile international is yet to sign a new contract with the Gunners amid rumours that he is a confirmed target for Bayern Munich.
And Parlour admits that he is worried as Arsenal cannot afford to lose such a key player.
"I was a little bit worried about him come the end of the season," Parlour told talkSPORT.
"Will he want to move on and go somewhere different? He's top quality and you want to keep those sort of players if you're going to be looking at the title next season."
Meanwhile, the 27-year-old says he struggled to get some sleep after Chile lost their opening game at the Copa America against Argentina.
"I'm tired," Sanchez is quoted as saying by Metro.
"I could not sleep after the match with Argentina. It was demanding.
"I hope to recover and get my enthusiasm back in the game against Bolivia.
"I hate to lose, even to Argentina, who are a world power. I think about the game [all night]. I only slept for about four hours."