Pakistan were blanked 3-0 by England who won the third and final game in Sharjah in a thrilling Super Over finish on Monday -- leaving Waqar to ponder his side's progress just four months before the World Twenty20 in India.
"I think it's a big eye opener," said Waqar. "We have seen a lot of things which were not obvious before and there was an obvious difference between the two teams.
Pakistan were cruising along nicely in their chase of a 155-run target but faltered in the last over, leaving scores level at 154.
Chris Jordan conceded only three runs in the Super Over which England overhauled off four deliveries.
Waqar praised England.
"England were younger than us and fitter and I think that made the difference. Credit to them for bouncing back after losing the Test series," said Waqar whose team won the preceding three-Test series 2-0 but lost the four-match one-day 3-1.
"Twenty20 is fast cricket and that's why we couldn't match them," said Waqar of England who have now won six consecutive Twenty20 matches and displaced Pakistan to sixth from second in T20 rankings.
"I don't know, I dont have the answer why they are not performing," said Waqar of Umar who was initially dropped from the team for a discipline violation.
"They are not young like 18 or 19 and as far as the opportunities are concerned everyone, selectors and cricket board, know they get the most opportunities so I think selectors will have to think.
Umar and Sohaib Maqsood managed just 26 each while Ahmed
Shehzad scored 32 in three matches.
Waqar said his players were committing schoolboy errors.
"The manner in which they got run out is a schoolboy error, it's not that you are playing new players, these players are seasoned and that's not on, to be honest.
"Individuals have to think, are they worried about getting out? it's a worrying sign and if individuals come under pressure like this then its not good for them as well as for the team.
Waqar pointed out fitness as the key problem.
