Former Bayern Munich boss Ottmar Hitzfeld has told Sport Bild that buying Arsenal star Alexis Sanchez would make the Bundesliga champions "a better team."
But Hitzfeld, who led Bayern to five Bundesliga titles and a Champions League crown, said the club needed to move quickly to secure a good deal for the Chile international.
"He [Sanchez] is a player in the category that can make Bayern a better team," he said.
"But it's important to make decisions as quickly as possible, because the longer you wait the more expensive a player becomes.
"If a player is touted on the market over a period of weeks, his price rises enormously."
He said the arrival of Sanchez -- increasingly linked with a move to Bayern -- "would block somebody else's path into the team" and added: "If you do sign him he has to play, meaning another top star sits on the bench."
Bayern have made four signings so far this summer, adding midfielder Corentin Tolisso from Lyon, former Arsenal winger Serge Gnabry from Werder Bremen and Niklas Sule and Sebastian Rudy from Hoffenheim.