Mohammad Amir has left for England to join Pakistan's training group in Derbyshire after he returned two negative coronavirus tests.
The left-arm paceman is accompanied by masseur Mohammad Imran for the flight to England as the latter is categorised as a low risk after having recovered from the virus.
Amir had initially withdrawn from the series to spend time with his wife for the birth of his second child. Following the birth of his daughter last week, the 28-year-old seamer expressed his willingness to represent Pakistan in the upcoming T20I series.
The selectors then roped in Amir at the expense of rookie fast bowler Haris Rauf as he has repeatedly tested positive for Covid-19. Rauf was declared coronavirus-positive at the end of the first round of testing last month and has since returned positive results five out of six times.
Amir will be allowed to integrate with the national side once he tests negative for the virus twice in England during the five-day mandatory quarantine period.
Pakistan's extended squad is currently engaged in preparations for the three-Test series due to commence on August 5. The players took part in a four-day intra-squad warm-up game from July 17-20 with the second match set to begin on July 24.