Mark Robinson admitted his frustration as the Bears relinquished a strong position in their defeat to Surrey at the Kia Oval.
Heading into the final day, Warwickshire held 207 run lead with experienced Sam Hain (87*) and Will Rhodes (72*) well set.
But from 270 for four to 310 all out, the Bears were left stunned as Kemar Roach worked his way through the line up to ensure the hosts could reach a realistic target.
“You can’t lose six wickets in thirty minutes, no matter how well Roach has bowled,” said the First Team Coach.
“You shouldn’t do that. When all that happens with the mood of the game, the decisions seem to go with it. Sam was desperately unlucky, but we’ve got to be better than that. All of the good, hard work we’ve done is gone.
“In some ways it mirrors what’s been happening of late. From a batting point of view we’re doing well but we can’t get through periods of pressure or find that killer partnership.
“With the ball we started poorly in the first innings, but we did get ourselves back into the game with those partnerships until we got blown away in 20 minutes by Roach.
“Everything is uphill then and Rory Burns does what he does as an international player by sort of nullifying you. We did OK with the ball, we missed the bat enough and Liam got the edges, but nothing went to hand.
“Honestly, we shouldn’t be defending 240, we should be defending 300.”
Robinson will now lead his players into the Royal London Cup, before returning to LV= Insurance County Championship action for the final three games.
The tournament is a big opportunity for silverware with senior players ready to step-up and gain form ahead of the red ball finale.
“There’s an opportunity to regroup and to play better really,” Robinson concluded. “We’ve bowled poorly all year for the exception of Olly Hannon-Dalby as our wicket economy rates haven’t been good. We need to tighten up in that sense.
“When you lose, your confidence gets affected and these 30, 40 partnerships have got to be 120, 130s in terms of where we want to be which is beating Hampshire and Surrey where they are currently.
“Liam Norwell in some ways shouldn’t have played in this game as he’s massively short of overs, but we felt we needed his wicket-taking potential. We hope to keep him fit and he’ll play in the 50-over competition to help him attack the last bit of the summer.
“Nathan McAndrew has fitted in beautifully, he’s a real trier and we wish him all the best on his return to Australia. I think Farby is a long way down the line in getting a player he wants to try and give us that firepower.”