The Scottish side are reportedly keen to take Buttner on loan for the season.
Buttner’s agent Aleksander Bursac told STV Sport: “Yes, Celtic would like to take the player on loan for the season. We feel it would greatly help the boy’s development to be playing regularly at that level and in European football.
“Celtic are a really great club. They (Celtic) have been back and forward in dialogue with Manchester United. It’s in their hands now as we are not sure if they want to release him.”