The 23-year-old’s excellent form in the centre of the park this season saw the Kirkcaldy side offer him a contract extension to the end of season 2020-21.
Spencer has played in all but one of Rovers’ competitive matches this season since joining from Forfar on an initial one-year deal in the summer. He has scored one goal.
Speaking to the club’s website, manager John McGlynn said: “Brad has been impressive since he walked into Stark’s Park in June for pre-season training.
“He did really well during pre-season and has continued to improve.
“He has the most assists in SPFL Ladbrokes League 1, so he sees passes and can make them.
“He’s enjoying his football and as soon as we mentioned extending his contract he jumped at the chance to work here until at least the summer of 2021.”