Pakistan's new bowling sensation Yasir Shah has paid tribute to Mushtaq Ahmed, crediting the former spin maestro for his recent success in international cricket.

Yasir picked up 24 wickets in three Tests against Sri Lanka and in the process became the fastest Pakistan bowler to 50 scalps, beating Waqar Younis, Shabbir Ahmed and Mohammad Asif. He now has 61 wickets to his name from only 10 games.

But behind Yasir's meteoric-rise were a lot of tough times and at one point in 2011, when he made his ODI and Twenty20 debut, the legspinner had lost faith in his abilities.

"I made my debut in 2011 and played just one ODI and two Twenty20s. I simply did not think my bowling was up to international standard," the 29-year-old said in an interview in the International Cricket Council show Cricket 360.

That's where Pakistan's former leggie Mushtaq Ahmed, who played 52 Tests and 144 ODIs for the country, came in. He is currently the team's spin bowling coach.

"Mushtaq worked on my action and I can say he's the reason why I was so successful [in Sri Lanka]," Yasir said.

"We simply worked on line and length, and the exercise meant I was repeating my action over and over and my rhythm was back."

Yasir admitted he was nervous when he made his Test debut against Australia in October 2014. The prospects of facing off against the likes of David Warner and Michael Clarke had provided for some anxious moments. But he found great support in Mushtaq in that instance as well.

"Mushtaq and Wahab Riaz came up to me during our training session before the first Test and motivated me. They told me that that the Australians would try to unsettle me and attack my bowling and in the process give me their wickets."

Yasir started hesitantly but ended up picking up 12 wickets as Pakistan whitewashed Australia 2-0.

The momentum gained from bringing down the mighty Aussies ultimately helped him put in brilliant performances against Sri Lanka where Pakistan won its first Test series after a gap of nine years.

"At the start of the tour, Misbah told me that it had been nine years since we won a series in Sri Lanka. But I was confident that we had the talent to go all the way this time."

"The practice games helped me. I did not pick up wickets initially so I decided to concentrate on blocking the runs and creating pressure. The wickets eventually came."

And they came in thick and fast. Yasir picked up his 24 wickets at average of 19.33 from the three Tests against Sri Lanka.

But Pakistan new star is not reading too much into his impressive stats and has vowed to stay grounded.

“It hasn't been an easy ride. And I don't look at stats too much ... I'm the fastest to 50 and stuff like that.

“I plan for every single game and what areas I will be concentrating on when I bowl. I will keep doing that.”