Northern Ireland boss Lawrie Sanchez said the 1-0 defeat at home to Canada could be the "kick up the backside" his team needed before facing England.
Sanchez's side went down to a first half Olivier Occean header, scored after Canadian defender Gabriel Gervais had been sent off.
"Our fans and sometimes our players believe their own press, but this was a dose of reality," said Sanchez.
"There was no invention in the box. We played to our ranking."
Sanchez picked out Aston Villa's Steve Davis as Northern Ireland's best player on what was a disappointing night at Windsor Park.
"Steve had a decent debut. If you had to choose one player from that team it would be him. He looked a Premiership player," said Sanchez.
"Let's be realistic, we bossed 90 per cent of the game. We had plenty of possession but our crossing was poor.
"This is not morale damaging, it could be the kick up the backside we needed before the England game."
Captain Aaron Hughes said he was confident Northern Ireland could lift themselves for the 26 March Old Trafford qualifier.
"It is disappointing to lose but England is a big one for us and we must put in a better display," said Hughes.
"We rushed too many things when we needed to be patient."
"We had a lot of the ball and were unlucky in that David Healy and Steve Jones both hit the post.
"But we keep conceding bad goals and we need to improve on that because a team of England's quality could punish us even more."
Canadian coach Frank Yallop was thrilled by his inexperienced side's performance.
"We are in a building process at the moment and this is a great result," said the former Ipswich defender.
"Northern Ireland had their chances but did not quite finish correctly, although they hit the post twice. The conditions were difficult, it was windy and slippery out there."