Mushtaq backed wrist-spin duo Yasir Shah and Shadab Khan to do the job in Manchester.
Yasir returned with figures of 4/66 and Shabab bagged 2/13 to help Pakistan dismiss England for 219 and take a significant 107-run first-innings lead.
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The pair is expected to be "lethal" for the home team batters on a deteriorating surface even in the second essay at the Old Trafford.
By stumps on Day 3, Pakistan stretched its lead to 244 runs, being 137/8.
Mushtaq lauded the fact that both Yasir and Shadab were able to quickly find their best rhythm despite not playing top-level cricket for so long prior to this series.
"Yasir and Shadab have hardly played much cricket for the last five or six months, but the way they bowled in the first innings I think they've got the momentum now," the former leg-spinner told reporters.
"They understand the pitch and what pace you need to bowl on it, what fields you need to have to different batsmen. I think they are feeling confident in their bowling now."
Yasir ran through the English lower middle-order in virtually no time to hand Pakistan substantial advantage.
"Yasir especially, I think he started a bit nervously but we can understand that and I think he then bowled well and now if we set a good target, they (him and Shadab) can be lethal out there," Mushtaq added.
Before going out there to defend Pakistan's target, Yasir (12*), who made a hundred in Adelaide on last winter's trip to Australia, has the responsibility to try and add as many crucial runs as possible alongside tailenders Mohammad Abbas (0*) and Naseem Shah (yet to bat) early on Day 4.
(Inputs from AFP)