Hart believes Piquionne is now starting to adapt to the demands of English football.
He said: "John Utaka pulled out on the morning of the game with an adductor strain so that was a late change.
"We were going to try to give Aruna a bit of a rest but he had to play. The penny is starting to drop with Frederic. We have a lot of players who haven't played in the Premier League and it's a massive change for them.
"There's an English attitude to the game that Frederic has to acquire.
"His goalscoring record in France wasn't the best but he's got other things and we hope he'll begin to make goals for people as well."