Williamson was already set to miss the third game on Wednesday, and with the first Test against South Africa less than three weeks away, Stead said his star batsman would probably sit out the final two games as well.
“With the test matches so close as well and in the big scheme of things (they are) a higher priority I think we’ll try and make sure he’s right for that,” Stead said.
Tim Seifert is expected to replace Williamson in the batting line, with Stead indicating Seifert was already set to replace Devon Conway as wicketkeeper at some stage in the series.
New Zealand is currently leading the five-match T20I series 2-0 and will look to seal the series in the third match on Wednesday.
Finn Allen and Devon Conway
New Zealand set Pakistan to chase 195 runs after getting a flying start as Finn Allen and Devon Conway raised 59 runs for the first wicket inside the powerplay.
Williamson joined Allen after Conway’s dismissal, and together they added 52 runs to the total before the former pulled his hamstring and retired hurt after scoring 26 off 15 with three boundaries and one six.
Allen continued his onslaught, scoring his third T20I half-century in only 24 balls but was castled by a brilliant googly by Usama Mir.
He played an exhilarating innings of 74 runs from 41 balls, laced with seven boundaries and five sixes.
Abbas Afridi then removed Daryl Mitchell (17) and Mark Chapman (4) off consecutive balls spanning over his two overs to pull the scoring rate down.
Mitchell Santner hit Aamir Jamal for 14 runs in the 18th over before Haris Rauf bowled a three-wicket over to reduce New Zealand to 187-7.
Santner’s 25-run cameo ended with a run-out in the final over as New Zealand finished their innings at 194-8.
Harif Rauf returned with bowling figures of 3-38, while Abbas Afridi picked two wickets for Pakistan.
In response, Pakistan started the chase miserably, losing both openers inside two overs with only 10 runs on the board.
However, Babar Azam and Fakhar Zaman helped Pakistan recover with a counter-attacking partnership of 87 runs from 49 balls.
Blistering Innings of 50 off 25 Balls
Zaman led the charge with blistering innings of 50 off 25 balls, featuring three boundaries and five sixes before getting an inside edge off Milne which crashed his stumps.
New Zealand bowlers dominated from there and picked quick wickets to reduce Pakistan from 97-3 to 125-6.
With Pakistan needing 70 off 33, Babar Azam and Shaheen Afridi (22) knitted a brief 28-run stand, which looked to take their team out of trouble but the former mistimed Ben Sears and was caught by Tim Southee at Southee at mid-off.
Babar Azam scored 66 runs from 43 balls with the help of seven boundaries and two sixes.
Adam Milne dismissed Afridi and Usama Mir on consecutive balls before Southee picked the final wicket of Abbas Afridi to wrap Pakistan’s innings at 173.
Milne led the bowling for the Kiwis with the figures of 4-33.