The 30-year-old Gul had his career derailed by a knee operation last year and in his return early this year he failed to impresss.
Pakistan’s chief selector Moin Khan said Gul and Riaz’s return will bolster the squad for the two Twenty20 matches in Dubai on December 4 and 5.
The Twenty20 will be followed by five one-day internationals.
“Gul and Riaz are making comebacks from injury to make the pace attack more potent and I hope the squad will do well considering next year’s World Cup,” Khan said in a Pakistan Cricket Board release.
Also returning to the one-day team is 37-year-old Younis who amassed 468 runs in the 2-0 win over Australia last month.
That came on the back of his controversial axing from the three-match one-day series against Australia in which Pakistan were white-washed last month.
Another paceman Wahab Riaz is also in both the squads after suffering a knee injury in the one-day series against Australia while opener Ahmed Shehzad returns after suffering a head injury in the first Test against New Zealand.
New Zealand beat Pakistan by an innings and 80 runs to level the three-match Test series in Sharjah on Sunday.
Pakistan squads (Twenty20): Shahid Afridi (captain), Ahmed Shehzad, Anwar Ali, Mohammad Hafeez, Haris Sohail, Mohammad Irfan, Owais Zia, Raza Hasan, Saad Nasim, Sarfraz Ahmed, Sohail Tanvir, Umar Akmal, Umar Gul, Wahab Riaz
One-day: Misbah-ul Haq (captain), Mohammad Hafeez, Ahmed Shehzad, Asad Shafiq, Bilawal Bhatti, Haris Sohail, Mohammad Irfan, Nasir Jamshed, Sarfraz Ahmed, Shahid Afridi, Sohail Tanvir, Umar Akmal, Umar Gul, Wahab Riaz, Younis Khan, Zulfiqar Babar.