The Senegalese midfielder has scored four goals in five appearances since joining the Tigers from West Ham United on transfer deadline day, including one against Arsenal in their 2-2 draw on Saturday.
Davies has admitted that he has been surprised by the quality that Diame has brought to the KC Stadium.
"He's been brilliant. His quality, his composure, he's definitely added to our squad," Goal.com quotes Davies as saying. "I was expecting a hustle-and-bustle midfielder, a strong, get-about player. I thought the goals would come but to get four in five is ridiculous.
"Arsenal were meant to get him on about two or three occasions. I'm not sure if it was something to do with the medicals. He nearly went there when he was at Wigan and West Ham.
"I don't know why it didn't happen but I'm delighted it didn't and that he came to us instead. I'm particularly delighted he's travelled halfway round the world this week, put in that performance and scored a composed goal like that."
Hull have moved up to 11th place in the Premier League following the draw.