Fletcher's side are currently outside of the relegation zone courtesy of goal difference, but must pick up points against their rivals if they are to beat the drop.
"The support is vital and it makes such a massive difference - the players appreciate it so much," he told the club's official website.
Argyle President Chris Webb added: "The excellent away result at Accrington last Saturday gives the Pilgrims renewed belief that we can stay up this season.
"This result gives us distance from the drop-zone bringing us closer to safety.
"Together, we can put our club back where it belongs."
