Gul took a career best 5 for 31 to help Pakistan win the second Test in Lahore and draw level with India at 1-1 in the three-match series.
The final encounter is due to start on Tuesday in Rawalpindi.
"We have to name a 17-man squad after injuries to some key players with Gul also ruled out due to a back problem," said chief selector Wasim Bari.
Fast bowler Shabbir Ahmed is nursing a shin injury, while experienced wicketkeeper Moin Khan and allrounder Abdul Razzaq were earlier ruled out of the final Test after failing to regain fitness.
Moin and Razzaq played in the first Test at Multan but pulled out of the second Test with the former suffering a groin injury and the latter hit by back ache.
Bari admitted he was concerned with the injuries to frontline players ahead of the crucial Test.
"The injuries are worrying but I am confident the boys will put this behind them and display the same standard of cricket that earned them victory," Bari said.
India won the first Test at Multan by an innings and 52 runs while Pakistan levelled the series with a nine-wicket win in the second in Lahore.
Pacers Rao Iftikhar Anjum, Fazle Akbar, Abdul Rauf, and allrounder Rana Naveed-ul-Hasan have been recalled as back ups.
Only Akbar has played for Pakistan before with his last of two Tests against New Zealand in 2001.
Third Test squad: Inzamam-ul Haq (captain), Taufeeq Umar, Imran Nazir, Imran Farhat, Yasir Hameed, Yousuf Youhana, Asim Kamal, Misbah-ul-Haq, Kamran Akmal (wicketkeeper), Shoaib Akhtar, Mohammad Sami, Danish Kaneria, Shoaib Malik, Rao Iftikhar Anjum, Fazle Akbar, Abdul Rauf, Rana Naveed-ul-Hasan.