Reynolds spent the past year with the Owls after moving from Motherwell in the January transfer window, but he has struggled to make an impact at Hillsborough featuring only three times this season with the League One side and has made just 14 appearances in all competitions since joining Wednesday.
The 24-year-old trained with his new team mates today and could feature in the Scottish Cup clash against Forfar on Saturday, if the paperwork is completed in time.
And it looks like Reynolds will take the place of Richard Foster, who is expected to sign for Bristol City after both clubs agreed a fee for the Dons skipper.
The deal is still subject to personal terms and a medical, but Foster will stay with the Pittodrie side over the weekend.
The defender, spent last season on loan at Rangers and has been with Aberdeen since 2003 making 294 appearances for Craig Brown’s side.
He made 24 appearances both domestically and in Europe for Rangers last season, winning a Scottish Premier League winner’s medal in the process.