Having addressed his concerns over the Reds' attacking options with the signings of Matt Derbyshire and Ishmael Miller, City Ground boss McClaren is now looking at the other end of the pitch after seeing the Hammers run riot in the first-half.
"We defended very poorly," he said afterwards. "We had opportunities in the other box.
"Today our weaknesses got exposed. It's up to us to address that on and off the field.
"You go nowhere with defending like today. We can defend better than this."
The international break and the looming transfer deadline gives McClaren the chance to work 'on and off the field' before the Reds are back in action at Southampton on 10th September.