Berahino, who scored the winning goal against Manchester United last weekend, is out of contract at the end of the season and a number of clubs are thought to be monitoring his progress at the Hawthorns.
West Brom are determined to tie the England Under 21 international down to a new long-term contract and McAuley believes it is vital they reward him with fresh terms to prevent speculation affecting his form.
"It is very important for Saido and for the club because he doesn't need speculation starting," McAuley told the Express & Star.
"He doesn't want anything that will make him take his eye off the ball.
"I'm sure there is a lot of stuff going on behind the scenes to get that sorted, and the sooner it's done the better."