It is understood 45-year-old Brewer will take up the role of head coach, working with current rugby director Kingsley Jones.
The Sharks' Guinness Premiership future is secure for another season after Worcester were doomed to relegation following a 12-10 defeat against Leeds Carnegie last Sunday.
But they are currently 11th with just one game remaining, a far cry from just four years ago when Sale were crowned Premiership champions.
Brewer, a former Scotland forwards coach during Frank Hadden's reign, won 32 caps for New Zealand and played in the 1995 World Cup final against South Africa in Johannesburg when the All Blacks lost 15-12.
He was also part of the New Zealand team that crushed semi-final opponents England in Cape Town six days earlier, a game remembered for wing Jonah Lomu's four-try demolition job.