McAuley’s deal has expired and the 35-year-old is now mulling over a one-year extension with the Baggies.
The defender has attracted interest from clubs including Leicester City, but Brunt hopes his Northern Ireland colleague remains at The Hawthorns.
Speaking ahead of Saturday’s European Qualifier against Romania, midfielder Brunt said: “I’m quite surprised it’s in the situation it is. It would be a no-brainer for me.
“He’s a guy who plays every week in the Premier League. People keep speaking about his age but if you see him day to day in training he’s an extremely fit lad.
“For the age of him he’s a bit of a freak really and for him to keep grinding the level of performance he does week in, week out…it’s just a no brainer.
“Ever since he got back in the side around Christmas time he’s never looked back.
“He’s pretty much been like that ever since he joined the club, so hopefully they get that sorted.”
Northern Ireland lie second in Group F, a point behind leaders Romania.
Watch Northern Ireland v Romania live on Sky Sports 5 at 7.45pm on Saturday.