The team's management said the 22-year-old would undergo CT tests and would be kept for the next 48 hours.
However, the Pakistan Cricket Board (PCB) later said that the scans showed that the player had not suffered damage.
"Imam-ul-Haq scans everything, he joins the team and stays under the observation of his team," piped the PCB.
On the field, the pacemaker Shaheen Shah Afridi scored his best bowling career while opener Fakhar Zaman struck half a century to help Pakistan win the leveling series.
4 – 38 of Shaheen kept New Zealand up to 209-9 in their 50th Championships before time came back and formed with a 88th ball run for his seventh fifty to guide Pakistan to their goal for the loss of four wickets in 40.3 overs.
Tywer, Ross Taylor, arrived in New Zealand with 86 heavy cards, and added 75 to the fifth team with Henry Nichols, who made 33 painful points of 63 balls.
With the Pakistan defeated four years to lose a row of 12 consecutive one-day international against Black Caps, starting with the 2-3 defeat of the United Arab Emirates in 2014.
New Zealand also beat Pakistan 2-0 (New Zealand 2015), 2-0 (New Zealand in 2016), 5-0 (New Zealand in January this year) and the first match for the current series at 47 runs in Abu Dhabi on Wednesday.
The win also sets an intriguing final game in Dubai on Sunday.
"We wanted to make a comeback and the team did it well," said Pakistan captain Ahmed Sarafarz.
"We held them with low courtesy of Shahin, and then Fakhar and Bar fought so well."
New Zealand Skipper Kane Williamson thanked his team for not putting a total to defend.
"A bit of junk that just put us in," he said. "It was not enough on the surface.
Zaman, who had 57 bad games in the last six days in the world, punished Baulers in New Zealand with 11 frontiers and gave Pakistan a quick start of 54 with an imam.
Zaman, unharmed by the Imam's injury, added 101 cards to the second game with Babar Azzam, who made a 50-ball ball before they both fell in the same Ferguson.
Ferguson, who finished with 3 to 60, had another lucky break from Schweib Malik to ten, when a cruel pull removed Nicole's shoulder and was caught in the middle by my confidant.
Sarfraz fell for 13 but Mohammed Hafiz hit the winning line to finish with 27 not out.
Earlier, Taylor Nicholas picked up New Zealand after Shaheen again rocked the top order after his 4-46 first game.
Shaheen rejected the devastating surprise Colin Munroe in the second round of the rounds, and turned around in a harsh perception of Hafiz.
In his next year he removed the direct drive to run out and Cain Williamson (one) at the end of the non-striker.
In his second magic, Shaheen taught Tom Latham for one, while Hafeez Bowling Jr. Walker for 28 leave New Zealand struggling for 73-4.
Taylor, who made 80 in the first game, held one end complete and together with Nicholas ensured that the rounds would not end below 200.
Nicholas was finally bowled at 38 by Hassan Ali who finished with 2-59.
Taylor struck three borders and six for his half-century in the 43rd international days.