Mick Newell admitted Notts had let Worcestershire off the hook with some poor catching on day one of their County Championship Division One clash at Trent Bridge.
His side were well placed when they reduced the visitors to 102-5 shortly after lunch.
But they then put down four chances, to allow Worcestershire to recover to 253-7 at the close with Matt Pardoe on 56 not out and Damien Wright unbeaten on 32.
"Four catches, all of which should have been taken, have cost ourselves a lot of runs and a lot of time in the field," said director of cricket Newell.
"Two of the three slip catches were very easy and the one at square leg was even easier.
"At 102-5 and then creating the chances by finding the edges, we should have been in a better position than we are in.
"If you take those catches then you would have expected to bowl them out for under 200 but we kept throwing the ball on the floor, which doesn't really help.
"Generally we are pretty good and we have caught some good ones up at Headingley and some good one here when Hampshire were dropping them, so I don't know how to explain it.
"I'm just very frustrated and I know the bowlers are very frustrated as well."
Newell feels Notts are still in a reasonable position should they bat well in their first innings.
He said: "We bowled tidily and they set out to score as many as they can in the first innings however long that takes them and that's fine.
"Ready (Chris Read) felt that we would be happy with bowling them out for less than 300, which is still the aim.
"It's a good wicket, I don't think it's done as much as the Hampshire wicket, and we can certainly make runs on it."
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