Strauss and coach Andy Flower have already set aside time for team meetings this week to prevent yesterday's dismal display — England were dismissed for a 121 — continuing in the one-day series.
The skipper added: "We've got to be very clear about our thinking.
"We need to have a couple of decent chats this week on how we're looking to play in different conditions and also how we're thinking and communicating out in the middle.
"It's one of those situations where you need to be calm, you need to take pressure off the players and allow them to go out there and play with freedom.
"That's the only way you can beat other international teams — you can't beat teams that are confident if you're not prepared to play with confidence and freedom yourself."
England will be without all-rounder Andrew Flintoff on Friday as he battles for fitness following his hip problems, while the West Indies were today boosted by the news that captain Chris Gayle should be fit to play after recovering from a hamstring problem.