The versatile Baptiste, who can also play right back or in midfield, missed much of last season through injury after signing a new deal last summer but with Mansfield Town's relegation to the Conference the 22-year-old put in a transfer request that has been accepted by the cash-strapped Stags.
Mansfield Town valued the player at £300,000 when Crewe Alexandra made an approach at the end of the 2006/07 season but that price is likely to have fallen following a disasterous season for The Stags.