Reports in Scotland have already leaked that the 23 year-old playmaker, who bagged 13 goals last season for the Scottish First Division side and won the divisional Player of the Year, has joined the Millers.
MillersMAD reported yesterday the fomer Celtic youth player and his agent were in Rotherham to finalise a deal and complete the necessary medical, whilst there were also reports of Tidser joining in the morning training session.
The left footed Tidser also spent a short time with Swedish club Ostersunds FK and has been capped by Scotland at U18 and U19 level.
More to follow as we get it.