[3] Born in Cologne, Baier first played for the youth team of TSV 1860 Munich.

He has played in the Germany national U20 team, his debut coming on 7 October 2005 against Wales.

On 31 January 2010, he left VfL Wolfsburg and returned to FC Augsburg.

[5][6] After 355 competitive appearances for FC Augsburg, Baier was released by the club on 23 July 2020.

This biographical article related to association football in Germany, about a midfielder born in the 1980s, is a stub.