Date of birth
Defender. Experienced centre-half who started out at Reading, but left in 2006 without adding to the 50 appearances he'd made during two lengthy loans with Kidderminster.
Mullins then spent two years at both Mansfield and Stockport before joining Rotherham in the summer of 2010.
He helped the Millers win promotion to League One in 2012-13, but left to sign for Oxford the following summer after a loan spell.
Mullins made 51 appearances in his last season, including leading the U's out at Wembley in the Johnstone's Paint Trophy final, as Oxford sealed promotion from League Two, before joining the Hatters with team-mate Danny Hylton.
The 31-year-old made his 500th career appearance in 2016-17, coming on as a substitute in the 1-0 home win over Accrington Stanley in November, although suspension and a hamstring problem made the second half of the 31-year-old's first campaign stop-start, limiting him to 29 appearances.