Datuk Seri Abdullah has to find a replacement for the post, which is regarded as an important portfolio. Deputy Minister Datuk Zulhassan Rafique, the MP for Setiawangsa, is currently holding the fort.
When Isa took charge of the ministry, it was not always smooth sailing, with City Hall officials insisting that politicians should stay away from the running of the city. Feathers in Umno were ruffled and relations have been bad since.
Abdullah surely wants the new appointee to sort out their differences to avoid complications that would not benefit the city folks.
The spotlight is also on two other ministries – Higher Education and Information – held by Datuk Paduka Kadir Sheikh Fadzir and Datuk Dr Shafie Mohd Salleh respectively.
The two ministers had to sit among the rest of the Umno delegates instead of on the stage during the recent general assembly as they are not on the supreme council.
Their failure to win a council seat in last year's assembly had caused much speculation as to how long they would remain in the Cabinet.
But holding top Umno positions does not guarantee one a Cabinet position. There has been a precedent as Datuk Zahid Hamidi did not get any government post under the Mahathir Administration despite being elected the Umno Youth chairman.
The popular Perak politician, who has been elected into the supreme council, is now a Deputy Tourism Minister.
But the sentiments of the grassroots cannot be ignored and those elected into high positions would surely clamour for these two Cabinet positions, which Abdullah may have to take heed.
Following the AP issue, a big question mark has appeared over Datuk Seri Rafidah Aziz, the longest-serving International Trade and Industries Minister.
She has been efficient in her ministerial duties. But the question now is whether the unhappiness of the Umno delegates over the allocation of APs would have an impact on her political future.
Then, there is the position of Datuk Mahadzir Mohd Khir, the Deputy Education Minister. The academician-turned-politician has not been well and it would not be a surprise if he is eventually replaced on health grounds.
The changes, according to speculation, are likely to happen in September as the MCA and Gerakan would have finished their party elections by then. The MCA is holding its polls on Aug 20 while Gerakan will be holding them on Aug 27.
Deputy International Trade and Industries Minister Datuk Kerk Choo Ting, who is Gerakan deputy president, will be challenged by vice-president Tan Sri Dr Koh Tsu Koon.
The popular perception is that Kerk would have an uphill task holding on to his position. His party boss Datuk Seri Dr Lim Keng Yaik has openly said his relationship with Kerk is strained. Should Kerk lose his party post, the likelihood is that he, too, would lose his deputy minister's post.
The MCA election is also being closely watched as president Datuk Seri Ong Ka Ting and his deputy Datuk Seri Chan Kong Choy are being challenged by vice-president Datuk Chua Jui Meng and secretary-general Tan Sri Dr Ting Chew Peh respectively.
There are also nine contenders for the four vice-president posts. The incumbents are Health Minister Datuk Dr Chua Soi Lek, Human Resources Minister Datuk Dr Fong Chan Onn, Deputy Higher Education Minister Datuk Fu Ah Kiow and Jui Meng.
The hopefuls are Deputy Youth and Sports Minister Datuk Ong Tee Keat, Deputy Federal Territories Minister Datuk Tan Chai Ho, Deputy Information Minister Datuk Donald Lim, Alor Star MP Datuk Chor Chee Heung, Serdang MP Datuk Yap Pian Hon and Sabah politician Chau Tet Onn.
The defeat of any of these MCA heavyweights could cost them their job as there are other Members of Parliament who would also be contesting other party posts.
For example, Datuk Liow Tiong Lai, who is contesting the Youth post, is likely to be groomed for higher office and the reward of a government position would come as no surprise.
As in any changes, the Prime Minister alone makes the decision but as the head of the Barisan Nasional, he would certainly take into account the recommendations of the party bosses.
Some have predicted that the changes would take place early next year, pointing out that Abdullah needs to focus his attention on tabling the Ninth Malaysia Plan in November first.
The changes in the Cabinet will surely come. The only question is when.