Durham one-day captain Dale Benkenstein has admitted the players struggled to handle the pressure of Sunday's CB40 semi-final defeat by Somerset.
Benkenstein and his team-mates posted a disappointing tally of 219 to beat, and Somerset achieved their rain-adjusted target of 165 to win by 39 runs.
"Getting to big days is great but we've got to learn how to cope," Benkenstein told BBC Newcastle.
"We've shown we can beat the best but it's being calm enough to perform."
The South African all-rounder added: "That is ultimately what we've lacked in the one-day campaign."
Despite falling short of the one-day and Twenty20 showpiece events this season, the County Championship remains one prize in Durham's sights.
Geoff Cook's side lead Division One by seven points, but have played one more game than their main rivals Warwickshire and Lancashire.
The two clubs have home fixtures against Nottinghamshire and Hampshire this week respectively, while Durham face an anxious wait before the final round of matches.
"It was a good comeback in the Sussex game, we've struggled a bit in the four-day games over the last two or three weeks," Benkenstein added.
"We showed a lot of character and given ourselves a great chance and this is our last chance.
"We'll be up for it at the Riverside in our last game [against Worcestershire] and praying for rain in the next seven days."
Durham host Worcestershire at Chester-le-Street from Monday, 12 September.