The midfielder had a relegation release clause within his contract which he has now activated to bring an immediate end to his time at the Keepmoat, just as Nathan Tyson did last month.
Boss Darren Ferguson said last week: "It's obviously a decision Richard has to make with the way his contract lies.
"If he did decide to stay, I'd be more than happy with that.
"He proved at the end of last season, and before that, he is a quality player.
"Richard just needs consistency and he didn't get that last season.
"But he's a player who can comfortably cope at this level and the one above."
Chaplow joined Rovers last summer following his release by Millwall.
He went on to make 30 appearances for the club, scoring two goals including a last gasp winner in the South Yorkshire derby with Barnsley in October.
The 30-year-old played regularly for Rovers towards the end of last season when Ferguson switched to a midfield diamond.