Monday night's Pakistan Super League (PSL) match between Islamabad United and Quetta Gladiators has been postponed to Tuesday after legspinner Fawad Ahmed returned a positive test for Covid-19. Ahmed had showed symptoms two days ago and had been immediately isolated, his franchise Islamabad United said. Other members of Islamabad United have returned negative tests, as have all members from the Quetta contingent. The start of the game, which was scheduled for 7.00pm local time, was originally put off by two hours, before the game was officially moved to Tuesday. A spokesperson of the Pakistan Cricket Board (PCB) told ESPNcricinfo that members of all franchises would undergo rapid tests on Monday which provide results within 15 minutes; all other Islamabad players as well as those from Quetta had returned negative results in these tests, while the other four franchises underwent them on Monday evening. On Tuesday, all franchises will undergo another test - the more widely accepted PCR test - and a special request has been made to process results of Islamabad and Quetta earlier so that, test results permitting, they can play their postponed game (Tuesday was originally scheduled to be a rest day). Until the end of the tournament, PCR testing will be carried out on all franchise players and officials in the bubble every four days. They were hitherto being tested on a weekly basis. This is this season's second Covid-related incident, and the second case of a player testing positive for the virus. On February 21, Peshawar Zalmi's captain Wahab Riaz, and coach, Daren Sammy, had been forced into a three-day quarantine after meeting a person outside the team's biosecure bubble. The breach had come three days after the PCB had briefed players, support staff and match officials to "religiously follow" all Covid-19 protocols. However, Riaz did not complete the mandatory three-day quarantine period, with Zalmi insisting their captain play the opening game, given he had returned two negative tests following the breach. Each PSL franchise has its own Covid compliance officer, who is responsible for testing, implementation of protocols, sanitisation, and players' temperature checks. The whole process is bring regulated by the event doctor. That incident highlighted what had been a concern for the PSL right from the outset. Despite extensive safety protocols set out to minimise the chances of a positive Covid-19 case disrupting the schedule, there has been concern around enforcement and observation of those protocols. A few days ago, a person interviewed on TV during the game between Islamabad and Peshawar Zalmi spoke of how he had "tried to high-five" as many players as possible. All players and officials - as well as families traveling with them in some cases - are part of a biosecure bubble in one hotel in Karachi. Each franchise nominated its own list of officials outside of the players to be part of the bubble, and everyone had to go through a three-day isolation period and return two negative tests before they entered that bubble. The other player to test positive, an unnamed cricketer from Lahore Qalandars, had gone into 10-day isolation on the same day and will need to return two negative tests and clear a fitness assessment before he can be re-integrated with the squad. This is likely to be the case with Ahmed as well. A PCB official confirmed to ESPNcricinfo that players and other members of the bubble would now be tested every four days till the end of the tournament. Ahmed had made his first appearance of this edition of the PSL on Saturday, February 27, during United's loss against Peshawar Zalmi. United's statement on his isolation suggests that would be the evening during which Ahmed went into isolation. Ahmed, who has represented Australia in ODI and T20 cricket, is a regular at the PSL and in leagues around the world. The 39-year-old came into this edition on the back of a long run of games in the Big Bash League for Perth Scorchers, including a miserly 1 for 16 in the final against Sydney Sixers.