Yasir has been far from his best in recent series, and his selection in the team has been a subject of debate. The 33-year-old did shine with the bat, registering his maiden Test ton at the Adelaide Oval earlier this month, but he couldn't deliver in his primary role as a bowler, returning just four scalps in 80.4 overs across two Tests in Australia.

But Mushtaq, who was appointed Pakistan's spin-consultant across all levels recently, said Yasir would soon rediscover his magic as a wrist-spinner.

Yasir Shah has managed just four wickets from three Tests in 2019

"He is not applying himself properly, and with a leg-spinner you always have to be patient," Mushtaq told ESPNcricinfo. "He has forgotten the process he used to follow while running in to bowl each ball. He has been impatient to regain his form as quickly as possible, and trying too hard to take wickets. He is pushing himself to live up to the expectations, and it is unfair that people suddenly started to doubt him, and he isn't getting a lot of support either."

Yasir is Pakistan's fourth-highest wicket-taking spinner in Tests, and was an integral part of Misbah-ul-Haq's Pakistan side that topped the MRF Tyres ICC Test Rankings for the first time in 2016. Mushtaq reiterated that it was unfair to judge a player based on his performance in one series.

"We shouldn't doubt our best bowler, who has taken 200-plus wickets for his country," said Mushtaq, who himself bagged 346 international wickets for Pakistan in a career spanning more than a decade. "He has been winning games for us, and you cannot just write him off on the basis of what he has done in Australia. Sometimes, it's about form, and sometime it's about pitches that aren't really helping you, but a good bowler remains a good player."

Yasir didn't make the XI for the ongoing Rawalpindi Test against Sri Lanka, and was released from the squad to work with Mushtaq at the National Cricket Academy in Lahore. Yasir will rejoin the team ahead of the second Test Karachi in Karachi.