The Senegal striker having bagged two hat-tricks since pitching up at St James' Park. Simpson feels his partnership with Leon Best is beginning to develop into a potent one.
"Demba's in great form," he told The Journal. "At the start of the season, with all his religion and stuff, he took a few weeks settling in, but look at him now. He looks strong, full of energy, he works his socks off and he's in the right place at the right time.
"And Besty played a part in all three of the goals, so it's a good partnership."