It has been reported by the British tabloid that Newcastle are in talks with Palace over the transfer of 26-year-old former Tottenham Hotspur winger Townsend.
Ritchie has been on the books of Newcastle since the summer of 2016 when he moved from Bournemouth for a transfer fee reported by BBC Sport to be worth £12 million.
The 28-year-old winger scored 12 goals and provided seven assists in 40 Championship starts for Newcastle during the 2016-17 campaign.
Last season, the Scotland international - who earns £45,000 per week as salary according to Spotrac.com - scored three goals and provided five assists in 32 Premier League starts for the Magpies.
Ritchie has done relatively well for Newcastle, but if manager Rafael Benitez is able to get £15m for him, then it would be a smart deal, as the Spaniard could invest that money in bringing back Townsend to St. James’ Park.