A rough diamond with the potential to make his mark at Old Trafford, the Holland Under-21 international will look to push for Patrice Evra's left-back spot.
After initially learning his trade with Ajax's fabled youth system, he moved to Vitesse Arnhem and made the first team as a raw 17-year-old.
Initially more accustomed to playing further up the field, he grew into the full-back role after a little initial reluctance, and still has a penchant for getting forward to aid the attack - something that should stand him in good stead at Old Trafford.
Having credited his father, himself a former professional in the Netherlands, for making great sacrifices to support his fledgling career, Büttner caught the eye in Arnhem and made Bert van Marwijk's preliminary squad for Euro 2012. The frustration at being cut from the final party must have been made harder to take with the fact that 18 year-old PSV Eindhoven defender Jetro Willems started at left-back during the tournament, becoming the youngest-ever player to appear at the European Championship.
After a transfer to Barclays Premier League new boys Southampton collapsed, he still hoped for a move before the end of the transfer