This is according to interim coach Augusto Palacios, whose successor at Mayfair is expected to be announced at a press conference at 11h00.
"It's natural [Manyisa's criticism] because he's the legend of the team and the captain of the team," Palacios told KickOff.com after the side's 2-2 draw with Cape Town City at Cape Town Stadium on Saturday.
"Sometimes he's not in the good form and he was also injured remember? It's all part of football and I have confidence in him and I hope the supporters do also. He is a good player not because he is a captain. But we are also trying to help him to become a better player," added the Peruvian.
Manyisa has battled to match expectations this season after a lengthy layoff through injury.
Pirates are also enduring a challenging campaign as they are 10th on the table with 20 points from 17 fixtures, having parted ways with Palacios's predecessor Muhsin Ertugral in November after a then-record 6-1 defeat to SuperSport United.
Palacios's time in the hotseat reached boiling point when the Buccaneers went down 6-0 to Mamelodi Sundowns in a fan-violence marred contest at Loftus Versfeld on February 11.