Hampshire captain Dominic Cork demanded improvement after his side's unconvincing win over Warwickshire in the Clydesdale Bank 40.
Hampshire beat Warwickshire by three runs with a score of 274.
"It's a win and that's the main thing, but there's certain things we've got to get right," he told BBC Radio Solent
"We're going to sit down and sort out how we can get better. 274 is a great score and we've been able to defend it but we should've got 300-320."
Having started their County Championship campaign with a draw against Durham and a nine wicket loss to champions Nottinghamshire, Cork says Hampshire need to adopt a more attacking mentality if they are to progress this season.
"We hadn't had a good championship game against Nottinghamshire and we came here and set up a great game, got three quick wickets and then just sat back," said the 39-year-old.
"That's what we can't do as a side, especially against champions like Warwickshire, who know how to play this game and know how to bat all the way through the order.
"We've got to make sure we are up for every occasion and we just sat off a little bit which I didn't like."