Edinburgh are set to appoint former Sale director of rugby Steve Diamond as their new head coach until the end of this season.
It had been anticipated former Scotland scrum-half Blair would step aside at the end of the season, but Diamond will now take charge immediately.
Blair is expected to remain part of the coaching set-up under Diamond.
The 41-year-old, whose contract expires at the end of the season, wants to focus on being an attack coach.
Diamond coached Sale from 2012 to 2020 and was latterly in charge of Worcester Warriors until the club entered administration in 2022.
The 55-year-old's first game in charge is set to be a trip to Connacht on 25 March, with Edinburgh currently sitting 12th in the URC table and facing an uphill battle to reach the play-offs.