Rizwan and Irfan both suffered hamstring injuries in the third match in Rawalpindi, where a second-string New Zealand side won by seven wickets to level the five-match series 1-1
The Pakistan Cricket Board and New Zealand Cricket (NZC) agreed to suspend the second day's play and finish the Test on Monday instead of Sunday.
"Today will be treated as a rest day, and the Test will resume tomorrow and conclude a day later than scheduled," NZC said in a post on their official twitter feed.
Pakistan, who lead the three-Test series 1-0, were to resume on 281 for three with opening batsman Mohammad Hafeez unbeaten on 178 and captain Misbah-ul-Haq on 38.
The 25-year-old Hughes was struck on the head by a bouncer during a domestic match on Tuesday and passed away after two days in hospital.