Yasir could face a ban for up to two years.
Yasir, currently ranked No. 3 in the ICC Test bowling rankings could face a ban for at least two years from the game.
The leg-spinner provided a sample to testers on 13 November, after the second one-day international against England in Abu Dhabi. It was found to contain chlortalidone, which appears in Section 5 of the World Anti-Doping Agency list.
This comes as another set back for Pakistan just when they had found an answer for out of favour Saeed Ajmal who had a big impact on the game. Ajmals bowling action was reported and subsequently he lost his wicket-taking ability with a remodeled action.
With the upcoming series against New Zealand followed by Asia Cup T20 and ICC T20 World Cup in March 2016, Pakistan could miss the services of Yasir if proved guilty by the ICC.
Yasir finds himself in a spot of bother as he is provisionally suspended and Pakistan Cricket Board will hope he comes out clean.