Toro Rosso tech boss James Key admits he was expecting more this season from the team's new-spec STR11 chassis.
With the exception of Bahrain, Carlos Sainz has been a consistent points-scorer this season for the Faenza-based squad.
While relative performance isn't all that bad, Key still underlines the car's aero as an area of weakness.
"I don't think we're as strong chassis wise as we have been for the past two years," Key told Motorsport.com.
"We're certainly some way off our maximum downforce at the moment.
"We're at the right levels for tracks like Barcelona, and we're very similar to the group of guys we're in. It could well be the same at Monaco.
"Having said that, I think the power thing will help us at Monaco, with the sensitivity, and it's traditionally a track where we've been reasonably competitive with the mechanical grip, and the way our balance works.
"And the drivers aren't bad there either, so fingers crossed, we'll get that right."
On the positive side, Key insists there is ample room for improvement.
"On the chassis side we're more immature than maybe we have been before with new regs," he said.
"Because everyone started last year – no one's had 18 months at this, we've all had less than a year effectively, because the regs didn't get agreed until just over a year ago.
"So I think we're at a slightly more immature stage than we were at in the past, and I think there are some fundamentals still to find in some cases."
“Want to win a trackday experience? All you have to do is subscribe to our FREE newsletter HERE”
GALLERY: All the action from Monaco
Keep up to date with all the F1 news via Facebook and Twitter
