Sale's poor start to the season continued with a sixth defeat of the campaign on Sunday and the pressure is beginning to mount on the Sharks as they sit third-bottom with just two wins and 15 points from eight games so far.
Diamond was not too critical of his side's performance at Welford Road as they lost 35-27, but he admits they need to be better in the final third.
"There was lots of good attack from us, but fair play to Leicester they didn't allow us to build a lead and they just managed to be a bit more clinical from us in the end. "With the results not going our way, it's not luck it's about us being more clinical and we probably infringed a little too often and we were penalized for it."
Diamond knows his side are better than their league positions suggests but he is aware results must now improve.
He added: "First-half we played really well but Leicester did what they do well and they pressurized us in the second-half. We're a good side but we need to get past the point of saying we are a good side and we need to win some of these games."