Ireland were "underdone and heavy-legged" in their humbling 57-15 defeat by England says head coach Joe Schmidt.
The eight-try loss comes less than a month before Ireland begin their World Cup campaign against Scotland in Yokohama.
"What really matters is in four weeks time," said Schmidt.
"You do get some disproportionate scores (in warm-ups), but we weren't good enough today."
Only New Zealand have inflicted a heavier defeat on Ireland, who are seeking to bring some momentum into their World Cup campaign following a lacklustre Six Nations.
At Twickenham, Ireland took the lead through a Jordan Larmour try but were outplayed in every facet of play from the moment Joe Cokanasiga crossed for England.
"There's a litany of things that were most disappointing," said Schmidt.
"We fell off 34 tackles.
"There was a little bit of positive (in the first quarter), but that score before half-time was key."
Healy ankle sprained but not broken
Ireland's misery was compounded by an ankle injury which forced loose-head prop Cian Healy from the field shortly before half-time.
After the game Schmidt confirmed that Healy ankle was sprained but not broken.
There was also concern for Conor Murray who required a Head Injury Assessment (HIA) following a collision with England wing Jonny May.
Having passed the HIA the Munster scrum-half returned to the fray but was replaced by Luke McGrath at half-time.
Ireland are still hopeful that Joey Carbery, who suffered an ankle injury in their opening warm-up game against Italy, will be fully fit for their Pool A opener on 22 September.