Convert boto3.resource(...) to boto3.client?

I found the following code in a class.

self.s3client = boto3.client("s3")
self.s3client.put_object(...)

And later the following code in the same class,

self.s3object = boto3.resource("s3")
obj = self.s3object.Object(BUCKET_NAME, LAST_DOWNLOADED_ID_KEY)  # use boto3.client?

Is it possible to convert the later one to use boto3.client so instance variable self.s3object can be removed?