"It's hard to find determination against an inexperienced Zimbabwe side but after they troubled us initially in the first game we will push them harder," Inzamam told reporters at a press conference on Saturday.
"You can't take international matches lightly," he said.
Zimbabwe, weakened by a crisis following April's strike by 15 white players, caught Pakistan napping at 36-4 and then at 146-6 before losing by 144 runs in the first match at Multan on Thursday.
Allrounder Abdul Razzaq hit a brisk century while Shahid Afridi notched a whirlwind 58 off just 26 deliveries to propel Pakistan to 292-7 to which Zimbabwe managed just 148.
"If you win against such an inexperienced side no one takes notice but when you lose against a weak side it's a big thing," said the Pakistan captain, who is a doubtful starter for Sunday's game due to groin injury.
"The injury is healing but I might rest for next week's game against Sri Lanka in Karachi," he said.
Asian champions Sri Lanka, who arrive in Pakistan on Sunday, are the third team in the tri-series in which all three teams face each other twice with the top two teams set to play the October 16 final in the eastern city of Lahore.
Pakistan, who rested their pacer Mohammad Sami in the first match, may also give express pacer Shoaib Akhtar a rest in the second match.
Zimbabwe captain Tatenda Taibu, who became international cricket's youngest captain at 20 earlier this year, said his side must grab any opportunity which comes their way.
"We had our chances at Multan but we did not grab them and against a side like Pakistan you can't spurn any opportunity," said the Zimbabwe captain.
"After the first defeat I want the boys to bowl well consistently and batsmen must occupy the crease for long," said Taibu, whose side suffered their 11th straight defeat at Multan.
Pakistan: Inzamam-ul Haq (captain), Shahid Afridi, Yasir Hameed, Bazid Khan, Salman Butt, Shoaib Malik, Yousuf Youhana, Younis Khan, Moin Khan, Misbahul Haq, Abdul Razzaq, Shoaib Akhtar, Mohammad Sami, Rana Naveedul Hassan, Rao Iftikhar
Zimbabwe: Tatenda Taibu (captain), Brendon Taylor, Vusimuzi Sibanda, Dion Ebrahim, Mark Vermeulen, Stuart Matsikenyeri, Alestar Maregwede, Mluleki Nkala, Elton Chigumbura, Edward Rainsford, Tawanda Mupariwa, Prosper Utseya, Douglas Hondo, Tinashe Panyangara, Graeme Alexandar Cremer