Remove feature image from top of posts but keep small image in archive

Hello everyone, I have attached a featured image to each post, as I want to have a small image beside each excerpt in the archive. I do not, however, want a large ‘cover’-type image on the top of each post. The feature image automatically appears as a large image at the top of each post and I wish to remove it. Is there any way of not having the feature image appear in large size above the post, but still retain the small image beside the excerpt in the archive? Any help greatly appreciated. Thankyou, Jim

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