Northampton centre Fraser Dingwall insists Saints are close to challenging the Premiership's best despite suffering three defeats in four games.
But they are currently eighth in the Premiership table following Sunday's 35-29 loss at Harlequins.
Dingwall told BBC Radio Northampton: "First half we were very loose and gave them way too many opportunities."
He continued: "The first half is not a reflection of what we want to be at all - it's a great example of us getting into the right areas and giving the ball away too cheaply over and over again.
"The amount of times we were in their 22 and gave the ball away cheaply without making them work is just unacceptable by our standards.
"When we get things right we're really creating chances, we don't need to go forcing things because when we play well we create so much and things are going to come our way."
Saints have also lost to Sale and Leicester, with their solitary league victory coming against London Irish.
"We're coming close but we haven't beaten the top sides in the league, that's the frustrating thing," Dingwall added.
"Performances like today you can get away with when you're playing sides who aren't pushing up at the higher end of the league.
"But when you play the top teams like Leicester, Quins, Sarries, you have to play well for 80 minutes because you can't give good sides a head start, it's too far to come back.
"We want to be in the top two, top four and that means we have to beat the top sides. We're ever so close, we just need to put performances together for longer periods of time."
Northampton are at home to Saracens in the Premiership Rugby Cup on Wednesday before travelling to financially-troubled Wasps in the league on Sunday.