Worcestershire Director of Cricket Steve Rhodes believes the 10.30am starts in Royal London One-Day Cup matches offer too much advantage to the sides bowling first.
Rhodes was speaking after Worcestershire's home clash with Derbyshire Falcons was abandoned because of heavy afternoon rain with Derbyshire 37-0 from 7.4 overs in pursuit of a 262 target.
Worcestershire were put into bat for the third successive One-Day Cup match after losing the toss and again lost early wickets in the bowler-friendly conditions before their middle and lower order brought about a recovery.
Rhodes said: "I think rain spoilt a good game. They got a very good start but they've got the power-play overs and it meant they could get off to a reasonable start so it meant they were probably just favourites.
"But there was a long way to go and I think it would have been a really good game of cricket.
"I think in all three of our games in this competition we've not pulled off the batting plans and that is disappointing.
"But what is pleasing is we have fought and scrapped and bashed our way out of trouble and got some sort of totals and we've got another one here which would have been testing still for Derbyshire.
"I'm a bit worried we are not playing to plans. That's a bit of a concern.
"But they've got to look at some rules in this which is the 10.30 start. There is too much advantage for the side bowling first.
"It nips around, you can lose two batters very early. We've tended to do that. There are two new white balls going and it's difficult for the side batting first.
"Then you saw again when they started their innings in the afternoon, it's a totally different game. I don't think it's a fair system."
Rhodes added: "Most sides are doing the right thing which is winning the toss and putting people in but we've lost three tosses out of three so it makes life difficult.
"If you lose two of your top order, you've lost two of your best six batters so it is quite effective.
"If you look back to those Lord's finals in September with a 10.30 start, the side that won the toss often won the game."
Worcestershire were rescued from being 73-4 in the 22nd over by a stand of 114 in 18 overs by Tom Kohler-Cadmore (71) and Ross Whiteley (53) before Ben Cox hit a rapid 39 off 24 balls.
Rhodes said: "Tom is only 19 and doing a good job, Ross has now had three fifties in a short space of time so very pleased with that, and Ben has been in pretty good form with the bat all year."
Gloucs Played 3, Won 2, Lost 1, Tied 0, No Result 0, Pts 4, Net Run Rate 0.137
Derbys 3, 2, 0, 0, 1, 3, 1.69
WORCS 3, 1, 1, 0, 1, 3, 0.485
Yorks 2, 1, 1, 0, 0, 2, 0.23
Leics 2, 1, 1, 0, 0, 2, 0.128
Essex 2, 1, 1, 0, 0, 2, -0.009
Hants 3, 1, 2, 0, 0, 2, -0.153
Northants 2, 1, 1, 0, 0, 2, -0.496
Lancs 2, 0, 2, 0, 0, 0, -1.95