Despite starting several games following his move from Lyon, Piquionne has been restricted to substitute appearances in recent weeks.
Hart said: "We've pulled Piquionne away from the first team to try and help him with a few things. He has done reasonably well in the reserves so he could have an opportunity to kick on a bit.
"But I don't want to single out strikers as the only means of scoring goals. We've all got parts to play and it's a team effort."