 MacDonald became the first player to score a hat-trick in the 2009–10 Scottish Premier League season by scoring three goals against Motherwell on 26 December 2009; MacDonald scored a "perfect" hat-trick of goals, scoring a goal with each foot and his head.He was injured in the act of scoring a goal at Rugby Park in February and his season was over.However, Peter was given a six-month contract to take him through to the end of 2010 and he worked hard towards full fitness with a reappearance in the first team coming towards the end of October.