Pakistan coach Dav Whatmore Monday said that losing the toss was key to his team's defeat to Sri Lanka in the second Test in Dubai as a low first innings score proved to be decisive.Sri Lankan captain Angelo Mathews won the toss and decided to bowl first, getting Pakistan out for a paltry 165.Sri Lanka, led by Mahela Jayawardene's 129, posted 338 to gain a big 223-run lead. Pakistan fared better in the second innings to score 359 but it only provided a meager 137-run target for their opponents.Sri Lankan achieved that for the loss of only one wicket to post their biggest-ever win over Pakistan in 45 Tests between the two nations.Sri Lanka now enjoy a 1-0 lead in the three-match series after the first Test ended in a draw in Abu Dhabi.Whatmore, a former Australian batsman who coached Sri Lanka to the World Cup title in 1996, said losing the toss was unfortunate."It was unfortunate to lose the toss as the wicket was helpful to the pace bowlers," he said."The wicket had been under the covers for nearly 24 hours previously (because of rain) which meant the batsmen were in for a difficult period on day one. Our first innings total was always going to prove difficult to defend," said Whatmore.Whatmore, who played seven Tests and one one-day international for Australia, defended not playing a second spinner in the Dubai Test."We always select the best possible eleven in relation to the pitch conditions. Unfortunately we could not play a second spinner and went in with three fast bowlers," he said.When asked if he agreed with skipper Misbah-ul Haq that Pakistan did not get the pitches they wanted in the series, Whatmore replied: "The short answer is yes."Whatmore said off-spinner Saeed Ajmal was unable to get a response from the pitches."Both Ajmal and Sri Lanka's Rangana Herath found bowling in Abu Dhabi and Dubai unresponsive," said Whatmore.Ajmal, who helped Pakistan to a 1-0 win over Sri Lanka in the last three-match series in United Arab Emirates in 2011 with 18 wickets, has so far managed just five in two Tests.Whatmore agreed Ajmal should be managed carefully."Ajmal will always need to be managed properly, as all match winning bowlers do. It would be incorrect to suggest batsmen are reading Ajmal," said Whatmore of the spinner who plays all three formats for Pakistan and is regraded as their main weapon.Whatmore, who ends his two-year tenure with Pakistan next month, hoped his team will be able to give him a winning send off."Conditions in Sharjah are likely to be different and will probably necessitate a change to the eleven," he said of his selection options.Pakistan are sweating on the fitness of paceman Bilawal Bhatti who injured his hamstring in Dubai. He is likely to be replaced by Mohammad Talha, while a couple of changes are also expected in the top-order batting which failed in Dubai.