The French forward has been in fine form in front of goal, scoring five times in nine appearances so far.
"He is always questioning himself," said Sagna. "He knows what he did well and what he did wrong. He tries to work on it during training sessions and tries to communicate with the boss.
"He is a very good player, good physically in front of the goal and finishes well. We need to give him time and I think he will improve even more, and be more decisive.
"Even with his English, he improved a lot and that makes a big difference."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball