Date of birth
The Wales international penned a two-year deal with the Millers ahead of the 2019/20 campaign, arriving as Paul Warne's second summer signing.
The 30-year-old boasts Championship experience from his spells with Swansea, Bournemouth and Wigan, and has also represented Wales on four occasions.
The central midfielder began his career at Swansea, taking in several loan spells at Yeovil Town where he played with current Millers boss Warne.
He joined Bournemouth in 2011 on a permanent basis, helping the club to two promotions from League One to the Premier League.
MacDonald switched to Wigan in 2016 and after three seasons at the DW Stadium, he has now penned a two-year deal with the Millers.